power circuits, transients that were belatedly identified as the cause of the in-field failures of the 

novel solid-state devices that were being introduced at that time. 

Nine available candidate commercial surge suppressors had been secured and subjected to 

breakdown or turn-on tests in order to compare their performance. Gap types exhibited the 

expected volt-time lag characteristics with or without self-clearing, while semiconductor types 

offered fast turn-on, but no self-clearing. 

Quote from the report: “There is a definite need to develop and promote a less expensive 

surge suppressor, which could receive more acceptance than the devices covered in this 

report.” 

Historical Notes: 

1. This report was formerly issued as GE ATL TIS Report.64GL174 (work performed in 1963). 

2. Some devices were priced over $8.00 (1963 dollars), severely restricting their application. 

3. Some other early sixties GE reports on related subjects are cited in this report, which are 

 no longer available but certainly represent obsolete information. The present report is 

 sufficient for the purpose of giving a historical perspective on the quest for a solution to the 

 problerms of translents-related field failures. 

4. The introduction of metal-oxide varistors was still ten long years away ...
power circuits, transients that were belatedly identified as the cause of the in-field failures of the 

novel solid-state devices that were being introduced at that time. 

Nine available candidate commercial surge suppressors had been secured and subjected to 

breakdown or turn-on tests in order to compare their performance. Gap types exhibited the 

expected volt-time lag characteristics with or without self-clearing, while semiconductor types 

offered fast turn-on, but no self-clearing. 

Quote from the report: “There is a definite need to develop and promote a less expensive 

surge suppressor, which could receive more acceptance than the devices covered in this 

report.” 

Historical Notes: 

1. This report was formerly issued as GE ATL TIS Report.64GL174 (work performed in 1963). 

2. Some devices were priced over $8.00 (1963 dollars), severely restricting their application. 

3. Some other early sixties GE reports on related subjects are cited in this report, which are 

 no longer available but certainly represent obsolete information. The present report is 

 sufficient for the purpose of giving a historical perspective on the quest for a solution to the 

 of translents-related field failures. 

4. The introduction of metal-oxide varistors was still ten long years away ...
AUTHOR 1 SUBJECT I NO. 

SCHENECTADY, NEW YORK - 

JIartzloff, FD I surge suppressors 

TECHNICAL INFORMATION 

SERIES 

' 

I l~arch 1967 

TITLE I G. E. CLASS 

KEY WORDS 

wervoltages, transients, surges, gaps, arresters, 

3uppressors 

Gvaluation of Commercial Surge Suppressor2 

ADDITIONAL COPIES AVAILABLE AT 

Distribution Unit, Bldg. 5, Room 345 

Research and Development Center 

P.O. Box 8, Schenectady, New York 12301 

I NFORMATI ON PREPARED FOR: 

CLASS 

2 

- 

NO. PAGES 

39 

Electronic Physics Laboratory 

SUMMARY 

Nine commercial surge suppressors have been securec 

~nd subjected to breakdown or turn-on tests in order to 

:ompare their performance. 

Gap types exhibit the expected volt-time lag characsistics with or without self-clearing, while semi- 

:onductor types offer fast turn- on, but no self- clearing. 

Most devices are priced above $8, which severely re- 

;tricts their application. 

There is a definite need to develop and promote a less 

zxpensive surge suppressor, which could receive more 

tcceptance than the devices covered in this report. 

This report was formerly issued as Advanced Techiology Laboratories Rept. No. 64GL174. 
Table of Contents 

Introduction 

Test Results and Discussion 

Conclusions 

References 

Detailed Device Evaluation 

General Electric Series 730B Spark Gap 

Cerberus UA1 Surge Arrester 

EG&G Fenotron 

Dale Surge Arrester 

Bell Gap 

Mark I Engineering Semiconductor Protector 

T. I. Klixon Semiconductor Protector 

Dressen-Barnes Overvoltage Load Protector 

Hunt SSS Switch (Power Device) 

General Electric Thyrector 
Introduction 

A number of surge suppressors which were advertised in the trade magazines 

were purchased for a limited evaluation of their performance. In the course of 

attempting to order several of these, it was found that some of the companies 

advertising these devices had either dropped the line or gone out of business 

altogether. 

Furthermore, in the course of discussing device performance or availability 

with representatives from companies still offering devices for sale, a distinct 

impression was gathered that these devices did not meet the acceptance which 

their makers had expected. This is not too surprizing in view of the prices 

which were quoted, even for volume purchasing. 

In some cases, rather fundamental questions such as the existence of a 

volt-time characteristic for the breakdown seemed rather startling to the 

company representative who answered the telephone inquiry, although he allegedly 

was a technical representative. Others, on the other hand, gave the impression 

of being quite sophisticated in this technology. 

Those devices which could be purchased were subjected to a consistent test 

for volt-time characteristic, which was the most conspicuously absent data from 

manufacturers' specifications. Other characteristics are generally well defined 

in the manufacturers specification sheets, which are reproduced in this report 

when available. 

The test circuit, consisting of a capacitor discharge circuit, is shown on 

the following page. 

All the devices which were tested are covered in separate sections of this 

report, grouping manufacturers specifications if any, g~neral description, 

typical performance oscillograms and a brief discussion of the device capabilities 

References are also made to other devices which were previously tested and 

reviewed in this program. 

Test Results and Discussion 

The detailed performance results will be found in separate sections which 

follow. For the purpose of presenting a general comparison, the most significant 

characteristics are tabulated below, including the Thyrector and Westinghouse 

device which were investigated in earlier reports. 

Manufacturer 

and Type 

GE 730B Gap 

Cerberus UA1 

EGM; Fenotron 

Dale LA9 

Bell 

West inghouse AP* 

Mark I SCP 

TI Klixon 

Dressen-Barnes 

Hunt SSS 

Type 

of 

Device 

Gap 

Gap 

Gap 

Gap 

Gap 

Gap & 

Varistor 

Solid 

State 

Sol id 

State & 

Breaker 

Solid 

State 

Solid 

State 

nonlinear 

Solid 

State 

Ratio of 

0.1 ps breakdown 

to min. breakdown - - 

160% 

250% 

Not defined 

600% 

140% 

over 400% 

Turn on in 40 ns 

Turn on in 60 ns 

Turn on in 90 ns 

Turn on in 50 ns 

No time lag 

Permissible 

Dissipation 

4 to 5 wsec. 

2000 amp. 

3000 amp. 

300 amp. 

? 

15 00 amp (?) 

15 0 

100 amp. 

100 amp. (? 

5 to 100 amp 

Self 

learin, 

No 

No 

No 

Yes 

No 

Yes 

No 

Yes 

No 

No 

Yes 

- 

Typical 

Price $ 

- 

8 to 16 

2 

5 

15 

Not av. 

2 to 3 

12 

18 

14 

2 

.75 to 5 

The gaps are characterized by their volt time performance; some are quite 

successful in producing a "flat" curve, i.e., the breakdown voltage at short 

times (0.1 p) is not a large multiple of the breakdown voltage at DC. The Dale 

device has combined an interesting arc-interrupting feature, which has not been 

* See TIS 64GL118 and references 

-3- 
investigated, however. On the other hand, this Dale gap has the worst volt-time 

characteristic. The General Electric series 730B gaps exhibit a relatively flat 

characteristic which make them quite attractive. The Westinghouse device, 

although self-clearing, was found to have questionable reliability, and also has 

a poor volt-time characteristic." 

Semiconductor devices are generally characterized by a fast turn-on time, 

which appears to be practically independent of the surge voltage. With increasing 

steepness of the applied surge, this means that an increasing voltage peak will 

be allowed to exist for a short time, while for surges with rise times longer 

than 0.1 bs, the clipping effect of the device will be near perfect. On the 

other hand, all these devices are latching. The Klixon is combined with a 

circuit breaker which will interrupt the power follow current (as well as overloads), 

with the corresponding added cost. The Dressen-Barnes and Mark I packages do not 

seem to offer for $14 any more features than the $2 Hunt device with the exception 

of a wide range of turn-on voltages. On the other hand, the Hunt device is not 

polarized and it is conceivable that it could be obtained, by selective grading, 

in a wide range of turn on-voltages. 

The Thyrector and other non-linear semiconductors (Zener diodes or selenium 

plates) offer interesting characteristics which were discussed earlier." 

RC networks are also effective surge suppressors, but their performance is 

intimately tied to the circuit parameters of the system in which they are applied. 

Under some circumstances, they can produce system oscillations so thatcaution is 

required in their use, while the other devices discussed here generally can be 

added to the system without unexpected interaction. 

*See TIS 64GL118 and references 
Conclusions 

The devices now offered for sale fall within two categories: gaps, with 

or without associated arc-extinguishing features, and semiconductor devices. 

Gaps exhibit their typical time-lag characteristic. Some designs appear 

more successful than others in reducing this undesirable limitation. 

Semiconductor suppressors have fast turn-on characteristics, often with no 

volt-time effect but rather with a constant time to turn-on. Their price is 

generally higher and not within attractive ranges for consumer type appliances. 

A number of firms which at one time advertised a line of suppressors have 

either dropped the line or gone out of business. indicating the difficulty of 

marketing suppressor components at the present prices. This indicates that 

there is a need to develop a low price suppressor. 

References 

Other devices than those reported here have been discussed in earlier 

reports written for this Program. These devices include: 

Reference 

Bendix Gap Cat TG98 TIS 62GL191 

W Lightning Arrester Cat 632A189A01 II 

- 

GE Signal Arrester Cat 9LA4C4 I* 

GE Secondary Arrester Cat 9L15CCB001 II 

Ledex Transient Control A-46800-001 I I 

Amperex Gap Cat 4369 II 

Hunt SSS 5 Layer Switch 63GL97, 64GL118 

GE DIAC 63GL197 

- W Appliance Lightning Protector 64GL 11 8 

GE Thyrectors 63GL97, 63GL144, 64GL118 

Also, see RCD application 

note 200.5; section 180, 

RCD spec. sheets. 
SERIES 73OB SPARK GAPS 

WITH STAINLESS STEEL OR TUNGSTEN ELECTRODES 

Rating: 60 Cycle Pwk Bwokdorn Vdmg. from 250 Volw t. bOm Vdrsta Custonn 6.r~l~rorm.n (Su Rern.. Ssdd 

Ud.rni1.r~' and C.S.A. Listinpv. ~mhuh~ rt ~pp~sramn ~ppl,... 

Th. m. or.hticdIy ..old-undf.cr.d k hunod~~. omolph.r#c condauon$, or k,.~~ prllcle.. 

hnl... at-1 &cmd.s m )or norm01 appl8setnns. Tungstm 4.ctmd.s ~~~1061. lor h.ary duvy qpltcotion.. 

hnc. @st* em m opm ~8rrvit wI!ch, unbl ntd rlts. 13 .xce.ld. or rh~h tms ~h. gor br.oL. 

Lm. *..i&mq m .nqy diwpww p& w .n wtoprmtr souvc.. Ir rhm pwmm ..r.ss roltope 

b buildin. up .n .I*cweol .quopmt cnn.ctd I. ,he cwwr bllermp ~h. sop 

Arc ts LnLn en supp.msin( so.. 

Aprlleatml Wr. my hen.i.nf dhq. pntrtia ,I r.qu8r.d (or m. .l.<lrsraI .d.ty 01 wltr .uch .I 

- c6sIlr sendn..rl, hmshnyr., N).. enddr .I~tllc~I 3wm.N 

b Y. of wl)l apn*ctor. I.*#s., other -p.n.nt. may 6. urm1ai.d ot no.mum rotsnss a9 4h.w rmall.s1 

. .I.. 

S*ml... m-1 .I-& per em nlrah mnnuus &.chors. d 4 ran second. a1 mrsv. A smlst 

liwr. br 1unp.m sqs 0. 25 r.11.. 

SERIES 7308-SPARK GAPS-DETAILED DATA 

CATALCG NO. VOLTAGE DWENSIWS 

- A (Max.) - B (Ma,) 

STAINLESS STEEL ELECTRODE 

-1m 

3250t165 687 

Y~~ZW 654 

(000f4M 687 

4303 + 430 ,687 

4X.l r 450 687 

5aWLr500 ,687 

6000*1iQO .a7 

TUNGSTEN ELECTRCOE 
GENERAL ELECTRIC SERIES 730B SPARK GAP 

Manufacturer: 

Specifications: 

Device principle: 

Accessory Equipment & Wlring Device 

Departments 

See AE-7305 sheets reproduced 03 

opposite page 

Hydrogen-filled gap, stainless 

steel or tungsten electrodes 

Available voltage ratings: 250 to 6000 volts 

Permissible surge current: Not specified--Total permissible 

energy per discharge is 4 watts-sec. 

for stainless steel and 25 watts-sec. 

for tungsten 

Will interrupt power 

follow current : 

December 1964 price: Stainless steel $8 to $9 depending on 

quantities 

Tungsten $16 to $17 depending cn 

quantities 
1100 volts applied surge 

Breakdown in 7 US 

1500 volts applied surge 

Breakdown in 800 ns 

2000 volts applied surge 

Breakdown in 80 ns 

with 1800 volts peak 

500 volts/div. 

0.1 ps/div. 

4000 volts applied surge 

Breakdown in 30 ns 

with 2900 volts peak 

1000 volts/div. 

0.1 ps div. 

Performance of 500 volts GE Gap 

Oscillograms showing applied surge with and without gap 

8 
Performance of the GE Gap 

The volt-time characteristic of a 500 volt gap is plotted below; typical 

oscillograms shown on the opposite page were recorded during tests for plotting 

this characteristic. 

The discharge capacity is stated as "continuous8' 4 watt-seconds or 25 wattseconds, which is somewhat ambiguous as a watt-second rating would rather imply 

a discrete total energy than a continuous rating. Actually, what is meant is 

that a number of single discharges at these energy levels may be applied without 

changing the breakdown characteristics. 

In spite of the statement "arc is broken in arc suppressing gas", the device 

is not self cleaning. 

Front of Wave -+Tail Time to breakdown - ps 

No breakdown could be produced with a single shot impulse below 1100 volts, 

however the breakdown voltage at 60 cps is 500 volts (crest). 

The 0.1 ps breakdown is 16077 of the minimum breakdown voltage. 
AMARK CORPORATION 129-11 18th AYENUXI COLLEGE POlNT. N. Y. 11%6 

TELEPHONE 212-762-lrw 

CABLD: AMABKCOILP NEW YDRK 

Edrl~argefallter Ueborrpannungrablelter rnit kleinet Storr-Anoprechopannung. 

Tube para-rurtenrion L barra tenrion d'unorpape. 

Rare gar fillad eurge rrrarter with especially low rerponr6 time. 

UEBERSPANNUNGSABLEITER UA 1 

TUBE PARA - SURTENSION UA I 

SURGE ARRESTER UA 1 

Technircha Daten DonnCe r techniqueo 'J'schnical data 

ZOndrpannun$ (stat. Anrprechrpannung) 

Tenrion doamorgage rtrtiqua 220 - 270 V * 

Static Breakdown voltage 

Stosr -An@prechspannung 

(Spmnungretorr mit 2 kV pr Anstiag) 

UA 1 

Nh 

2.16.13 DFE 

Tenoion d'amorprge au choc 

(Front du choc t 2 kV / )rs) 

cd. 

1.56 

Dynamic breakdown voltage 

(Voltage rislng with 2 kV / ps) 

lel. 

Betrrtbarkeit 

Charge admiribla 

Load 

Typircher Anwendungclbeirpialr Application typique: T yptcal application: 

tn jedsr Lago 

on tout porltion 

&ny position 

Anwendungsgebiet: Schutz von Schwachstromurlrgen und -Kabeln gegen Vebertpmnungen (Blltrschhg, ktmorphdrioehe Aafladungen, Kontakt mit Hochrp&nnungrleltungen etc,) 

Applications t Protection d~inrtlllationr A courant falble at de cablea 

centre Ies surt*nrionr (foudre, surtenrionr &tmosphdriquem, 

contact avac des Iignee do hhte tenrion.) 

Applicatlono t Protection of low-currant inotallationr and cabloo againat 

awrvoltayer lightning, ~tmorpheric,overvsltrgo~, ate. ) 
CERBERUS UA1 SURGE ARRESTER 

Manufacturer's Distributor: 

specifications : 

Device principle : 

Available voltage rating: 

Permissible surge current : 

Will interrupt power 

follow current: 

December 1964 price: 

AMARK Corporation 

See manufacturer's data sheet 

opposite page 

Rare gas filled gap 

One rating, 220 - 270 V DC 

2000A ( 50 p) 

10A (1 sec) 

$2.44 each 25-49 

$1.95 each 100-up 
280 volts applied surge 

Breakdown in 6 ps 

500 volts applied surge 

Breakdown in 150 ns 

1100 volts applied surge 

Breakdown in 50 ns at 800 volts 

4000 volts applied surge 

Breakdown in 30 ns at 1500 volts 

Performance of CERBERUS Gap 

Oscillograms showing applied surge with and without gap 
Performance of UA1 Arrester 

The device exhibits the typical gap breakdown characteristic, i.e., rising 

breakdown voltages at short times. 

Typical oscillograms recorded during tests performed for plotting this 

volt-time characteristics are shown on the opposite page. 

The current discharge capacity for relatively long pulse duration (50 ps) is 

substantial, but only one breakdown voltage rating is offered, so that the device 

is not very flexible. 

Furthermore, the device is not self-clearing, so that power follow current 

will have to be interrupted by other means such as fuses or circuit breakers. 

The volt time curve of the device is plotted below. 

Front of wave --+- Tail time to breakdown - ps 

There is good agreement between the test point and the manufacturer's 

specified breakdown levels. The 0.1 ps breakdown voltage is 250% of the 

minimum breakdown voltage. 
Data Sheet toll 

Tentative 

High Voltage Spark Gap for Protecting 

Silicon Diode Stacks from Over-Voltage 

1 / 2" Dia. 

Nominal 

Leads - 2" Nominal Length 

The Fenotron is an encapsulated, miniature, high voltage protective spark gap. The Fenotronls dependability and long-life make it 

especially suited for use in protecting silicon stacks from overvoltage. The device is a reliable, fast switching (40 nanoseconds) 

spark gap rebuiring no keep-alive voltage or trigger voltage. it 

operates at 800 V minimum with a voltage pulse rise time of 100 

kv/usec with 3000 amperes maximum peak current switching capa0111ty. 

A typical application for Fenotrons is to protect silicon diode stacks 

usedin clamping a trigger input voltage for Traveling Wave Tubes. 

Life of thousands of operations has already been realized. 

*EG&G Trade Mark 

EDGERTON, GERMESHAUSEN 6 CRIER, INC. 

160 Brookline Avenue Boston 15, Mass. 

COpley 7-9700 
EG&G FENOTRON 

Manufacturer 

Specifications 

Device principle 

Available voltage rating 

Permissible surge current 

Will interrupt power 

follow current 

December 1964 prices 

Edgerton, Germeshausen and Grier, Inc. 

See tentative data sheet on next page. 

Sealed gap, flat brass electrodes with ceramic 

spacer. 

One rating, not specified d,terms of steady-state 

3000 ampere crest 

$25 for samples - no large orders accepted at 

this time. Manufacturer estimated $5 for 

quantities if production were to start 
1500 volts applied surge 

Breakdown in 400 ns 

2000 volts applied surge 

Breakdown in 50 ns at 1100 volts 

500 volts/div. 

0.1 ps/div. 

Performance of EGG Fenotron Suppressor 

Oscillograms showing applied surge with and without suppressor 
Performance of Fenotron Gap 

No breakdown could be produced below 1500 volts applied surge; however, as 

the crest of the surge was raised, so that the front of the wave was steeper, 

breakdown occurred as low as 1100 volts. This particular point was obtained with 

a 20 KV/ws rise time (second oscillogram). With 40 KV/ps(third oscillogram), 

a step closer to the 100 KV/~ quoted on the data sheet as producing a "800 volt 

minimum" breakdown, the actual voltage at breakdown was 1500 volts. 

From the size of the electrodes, the current discharge ability seems rather 

limited, therefore the quoted 3000 amperes must be of rather short duration. 

Typical oscillograms are shown on the opposite page. Test points are 

plotted below; there is no apparent volt-time trend in these points and they do 

not correspond to the manufacturer's claims. 

0.01 ; 0.1 

Front of wave +, Tail 

1 

time to breakdown - p,s 
NEW PRODUCT 

TEMPORARY DATA SHEET packager 
DALE SURGE ARRESTER 

Manufacturer : 

Specifications: 

Device principle: 

Dale Electronics, Inc. 

Columbus, Nebraska 

See manufacturer's data sheet on 

opposite page 

Air gap with magnetic arc blow-out 

for follow-current interruption 

Available voltage ratings: Factory adjustable 500 to 4000 volts DC 

(%A-81 

or 1500 to 5000 volts DC 

(LA-9) 

Permissible surge current: 15,000 amperes (LA-8) 

300 amperes (LA-9) 

Will interrupt power 

follow current : Yes 

December 1964 price : LA-9, 500 volts 510% 

$16.90 ea. in quantities of 25 

$13.20 ea. in quantities of 200 
1200 volts applied surge 

Breakdown in 250 ps 

100 volts arc voltage 

(zero trace added for reference) 

200 volts/div. 

100 ps/div. 

1800 volts applied surge 

Breakdown in 1.5 ps 

2000 volts applied surge 

(2 shots) 

Breakdowns in 200 ns at 2000 volts 

and 75 ns at 1500 volts 

500 volts/div. 

0.1 ps/div. 

4000 volts applied surge 

(4 shots) 

Breakdowns in 40-60 ns at 3200 to 

4200 volts 

(highest breakdown trace higher than 

applied surge - see overshoots on 

2000 and 1800 volt traces above) 

Performance of DALE Surge Arrester 

Oscillograms showing applied surge with arrester in, single or multiple shot 

2 0 
Performance of DALE LA-9 Surge Arrester 

The device suffers from the inherent problem of all gaps, i.e., a substantial 

time-lag characteristic, as can be seen in the volt-time curve. 

Typical oscillograms recorded during tests performed for plotting the volt 

time are shown on the opposite page. 

On the other hand, the current discharge capacity of the LA-9 is substantial 

(300 amperes) and the device is self-clearing, in contrast to many of the suppressors covered in this report, which remain on after a surge-triggered turn-on. 

A small detail on the specification sheet: The device has two threaded studs 

which might be construed as the two terminals; inspection of the drawings, However, 

shows that the case is one terminal while the two studs are connected together. 

The author found at least one case where the user started to complain of shorted 

devices, while using the two threaded studs as the two terminals of the device! 

The volt-time curve of the device is plotted below. The 0.1 ws breakdown 

voltage is 600% of the minimum, with large variations between test points. 

Front of wave Time to breakdown - ps 

-2 1 - 
Performance of BELL Gap 

Oscillograms showing applied surge with and without gap 
BELL GAP 

This gap was loaned by Mr. E. R. Uhlig of the High Voltage Laboratory, 

as a gap obtained from the Bell Laboratories. No specifications were available, 

but it was implied that this was a 'qfastqe gap. 

Typical oscillograms recorded during the tests made to plot the volt-time 

characteristic are shown on the opposite page; the characteristic is plotted 

bklow; the very small rise in breakdown voltage for times as short as 0.1 p,s 

is remarkable, with the 0.1 ws voltage only 140% of the minimum breakdown 

voltage. 

Front of wave Tail Time to breakdown - pe 
SCP 

(Srl-Conductor ?mtoctor) 

Th. SCI ia no-llp w.4 In -awstion with standard fuse or u'netir reset 

circuit brehker. Zbare 1. mo ddirioo.1 reset circvit nccesmmry to remat the 

SCF. It *at-ttlatly r.mot* itaalf upon the replaseunt of the fun.. 01 thc 

r..cciv.ticm of the cirsult brmabr. 

(MSIC CIRCUIT OF OPERATIOW) 

- 

0 1 0 

(rl) Standard fume or magnetis sircult breaker. 
MARK I ENGINEERING SEMICONDUCTOR PROTECTOR 

Manufacturer: Mark I Engineering, Glendale, California 

Specifications : See manufacturer's specifications on 

opposite page 

Device principle: Three-terminal semiconductor turned on 

by Zener diode-resistor network in gate 

circuit ?-device is polarized. 

Available voltage ratings: .6 to 400 volts 

Permissible surge current: 150 amperes 

Will interrupt power 

follow current: 

December 1964 price: $14.10 for quantities up to 24 

$11.28 for quantities 100 and up. 
100 volts applied surge 

Turn-on in 40 ns with 80 volt peak 

300 volts applied surge 

Turn-on in 30 ns with 120 volt peak 

1500 volts applied surge 

Turn-on in 30 ns with 750 volt peak 

500 volts/div. 

0.1 ps/div. 

4000 volts applied surge 

Turn-on in 30 ns with 1600 volts peak 

Performance of MARK I ENGINEERING Semi-conductor Protector 

Oscillograms showing applied surge with and without protector 

26 
PERFORMANCE OF THE MARK I SCP 

The device exhibits a remarkable consistency in the turn on time, as well 

as a sharp firing point. The device tested had a 30 volt steady state rating, 

and began firing with as little as 50 volts. The oscillograms reproduced on 

the opposite page show that, over a wide range of voltages,the tim& required 

for turn on varies only from 40 to 30 ns. Following turn on, where the voltage 

across the device begins to depart from the no-load surge, the voltage continues 

to rise for a short time to reach a peak in less than 50 ns, The value of this 

peak is then determined by the rate of rise of the voltage since it appears that 

the the to peak is essentially constant for this device. 

A volt-time characteristic would essentially be drawn as an almost vertical 

line at 30 or 50 ns, depending upon the definition of the "volt at breakdown" 

which is the ordinate of this characteristic. 

Thus, this device offers an extremely fast and effective voltage limiting, 

although high voltages will still be reached if the front of the eurge is steep 

enough. For many practical circuits, however, 501 to 100 ns represents an 

extremely short rise time. 

On the other hand, the de\ice is not self-clearidg, and will depend on 

fuses or breakers to clear power follow current. 

Furthermore, the device in its present form is polarized, so that application 

to AC circuits might require two back-to-back units or two units with two reverse 

diodes in sertes. The manufacturer does not make any statement on the performance 

of this device with reverse polarity over-voltages. 
o~m.~rnl..lAIUI. ..01.01101 0. C0I.m OllOUll. II.84 01 0 1- OllDYll 

.1.."." -0.1 01 ..* r*.1.0...- 001.1.1.10" 

, ~rruat bnmhln m.7 h mmhlnrl wth ILIXON lRT I,, 4RT Ihm. 

.UU. PI1 9.80~u..d.1.ln.Ld.n)..mns ~r~r~mpn(urr~n.~m~~~~rnt 

h.uk.r I. -unW 8". nm*. lo..,"," 

m,., 

m.mrm =m. Ih. -lint ma.-aesnw tbm..~~ -.. ~de - 81,. KLIXON IH I 

and 4BT 'hw Sut"rrl- ace 8PST. h-8-ll? irl4 ,+w.,~ ,LII 

.m lrtow n1ahnt.d rla. I* rwv8t I,* t-pmtur. nr .I any mane UP 10 3M P whrn am .mrm,wnt,,r,. od9lhn u~n !n tk-prunt Lhr LL.rmc4~ .n.p thr cl.rual clad Thm mnwn nw- ruw.n8 n...k-,l 

In- Ihr .lMIIh."k...nl d.-nrr.l". Ih aul,mm.nl -w..., 
T . I. KLIXON SEMICONDUCTOR PROTECTOR 

Manufacturer : 

Specifications: 

Device principle: 

Available voltage ratings: 

Permissible surge current: 

Will interrupt power 

follow current: 

December 1964 price: 

Metals and Controls of Texas Instrument's, Inc. 

See manufacturer's specifications 

opposite page 

Two-terminal semiconductor turns on and 

clamps voltage; integral mechanical 

circuit breaker interrupts power follow 

current. 

12 - 60 volts; 115 volts might be 

available 

Not specified 

Yes 

$20.40 in quantities up to 100 

$16.85 in quantities 500 and up. 
280 volts applied surge 

Turn-on in 60 ns with 150 volts peak 

600 volts applied surge 

Turn-on in 40 ns with 300 volts peak 

2000 volts applied surge 

Turn-on in 40 ns with 1100 volts peak 

4000 volts applied surge 

Turn-on in 40 ns with 2500 volts peak 

1000 volt s/div. 

0.1 ~s/div. 

Performance of T.I. KLIXON Semiconductor Protector 

Oscillograms showing applied surge with and without protector 
Performance of Klixon SCP 

An overvoltage protector (type MC1) rated 30 volts DC was subjected to the 

test surges, as seen on the oscillograms~onthe opposite page. Turn-on occurred 

in less than 60 ns for all applied surges above 280 volts, which was the minimum 

surge voltage producing a firing, a rather high ratio to the rated DC voltage. 

A voltage peak followed the turn-on in a short time,with increasing talues 

as the steepness of the surge front was increased. 

This device is combined with a circuit breaker which can Also protect the 

load against overcurrents, in addition to tripping out the power-follow current 

after firing on a surge. In that respect, it offers attractive features for an 

otherwise unattractive price, but still a bargain compared to the voltage limiting 

only Dresser-Barnes units. 

The device is again polarized, with nb comment from the manufacturer on the 

performance with reverse polarity surges. 
Overvoltage Load Protector 

Protection of load against 

overvoltage transients from 

d-c source is application of 

Overvoltage Load Protector. 

It features 3-400v firing volt- as. 25% tolerance. surge 

current capacity of up to 100- 

amp for Ems, and standby 

current drain of 3ma. Am- 

, bient temp range is 0-IOO*C on atandard models and -55 to 100°C on special 

models. Dressen-Barnes Electronics Corp., Dcpt. EE, 

250 N. Vinedo Ave., Pasadena, Calif. 
Manufacturer 

Specifications 

Device principle 

DRESSEN-BARNES Overvol tage Load Protector 

Dressen-Barnes Electronics Corp. 

Pasadena, California 

See advertisement next page 

Semiconductor circuit turned on by 

surge. (2 semiconductors, several 

resistors and capacitors in 

encapsuLated housing) 

Available voltage rating 3 to 400 volts 

Permissible surge current 100 amperes for 8 ms 

Will interrupt power follow current no--m&cimum continuous power 

foll~w curpent is 3 tuA. 

December 1964 prices $14.50 in quantities up to 25 

$13.50 in quantities above 100 
280 volts applied surge 

Slow turn-on 

400 volts applied surge 

Turn-on in 90 ns with 

360 volt peak 

1100 volts app d surge 

Turn-on in 40 ns with 

700 volts peak 

4000 volts applied surge 

Turn-on in 30 ns with 

2000 volt peak 

Performance of DRESSEN-BARNES OLP suppressor 

Oscillograms showing applied surge with or without suppressor 

3 4 
Performance of Dressea-Barnes OLP Suppressor 

The device under test was rated 200 volts DC; firing or turn-on 

occurred with a minimum surge of 280 volts, with a relatively slow turn-on, as 

seen in the first oscillogram on the opposite page. Increasing the crest of the 

surge to 400 volts and above produced turn-on in decreasing time, from 90 to 

30 ns, followed by a peak voltage occurring in less than 50 ns. 

The device exhibits remarkable speed in turning on; however, as the steepness of the applied surge is increased, the turn-on time decreases only very 

little, so that increasing voltage peaks will occur. The minimum surge which 

will trigger the suppressor is only 140% of the rated maximum voltage, a ratio 

comparable to that of the less complex and slightly less expensive Mark I 

suppressor .' 

The device is also implicitly polarized, and the mahufacturer makes no 

Cment on the perfomance with reverse polarity. 1t wiil probably withetad 

a certain level of reverse polarity, but another unit will be required to obtain 

protection in both directions. 
HUNT SSS SWITCH (Power Device) 

This device has been investigated in earlier reports;* as it exhibits a 

definite turn-on action similar to some of the other devices covered in this 

report, it has been subjected to the same test series, in order toallow direct 

comparison. While earlier references were made under the name of SSS switch, 

this particular device is now called "power device" by the manufacturer. 

There are no specification sheets available from the manufacturer; their 

general catalog lists assembled hardware rather than components. 

This switch consists of a 5 layer, 2 terminal device, somewhat similar 

in operation to the DIAC. 

Prices quoted in 1964 were $2 each in quantities above 100. 

* See Tis 63GL97, 63GL144, and 64GL118 
140 volts applied surge 

Slow Turn-on 

280 volts applied surge 

Turn-on in 80 ns with 200 volt peak 

1100 volts applied surge 

Turn-on in 50 ns with 400 volt peak 

4000 volts applied surge 

Turn-on in 50 ns with 1200 volts peak 

Performance of HUNT SSS Switch 

Oscillograms showing applied surge with and without switch 
PERFORMANCE OF WUM: DEVICE 

The turn-on of the device occurs very rapidly for voltages above the rated 

turn-on. The oscillograms on the opposite page show how the turn-on, at first 

rather slow (lps), soon takes less than 50 ns when the applied voltage is 

raised beyond 500 volts. The turn-on starts as the voltage trace departs from 

the no-load trace, and is complete, i.e., the voltage is essentially clamped to 

zero, in less than 100 ns after the start of the turn-on. 

In contrast to some of the other semiconductor devices covered in this 

report, this one is not polarized. It is also very small and consists of a 

single component. The price is about 20% of that of the SCP and OLP semiconductor protectors, which are polarized. 

On the other hand, this device is not self clearing, power follow current 

will be established and will have to be interrupted by external means. However, 

the device can be quickly turned off by applying a reverse polarity for a short 

time, so that it is conceivable that a small iscillatory circuit could be 

added to the device; the oscillations of this circuit followirg the "chop" 

action of the device could then be used to turn it off. But this is a conjecture 

and not an existing device, which is what this report is intended to cover. 

In AC systems, of course, natural clearing will occur at the end of the 

first half cycle, so that power follow current is limited to the balance of 

the half cycle following the surge. This is discussed in detail in the 

reference reports. 
GENERAL ELECTRIC THYRECTOR 

This device does not exhibit a turn-on effect similar to the devices 

evaluated in this report and therefore cannot be directly compared to them as 

an individual component. Earlier reports* have presented its attractive 

characteristics through a comparison in a complete system such as the laboratory 

house model. The most significant characteristics are re-stated here Lor the 

convenience of the reader, while complete details will be found in the reference 

reports. 

While there is some limitation in the ability to suppress surges close to 

the steady-state voltage, the Thyrector and other non-linear semiconductors 

offer attractive characteristics such as the absence of any time lag,, in 

contrast to the volt-time effect of gaps and the turn-on time of switching 

semiconductors, plus the natural self-clearing action after disappearance of 

the surge so that there is no power-follow current. In addition, selenium 

devices have the unique possibility of self-healing after application of 

current pulses in moderate excess of their rating. 

Typical prices range from $ .75 to $5 depending on ratings. 

* See TIS 63GL97, 63GL144, 63GL118.