Component identification  - Page 1
Forum section: electronics / beginners

author: Jelcke
author_rank: Contributor
timestamp: September 10, 2018, 10:56:33 am
content: Hello,I came across a component (with four leads) that seems to have a capacitor network inside. Could anyone tell me what it is and wat it can be used for?Thanks,Jelcke

author: Benta
author_rank: Super Contributor
timestamp: September 10, 2018, 04:13:09 pm
content: Looks like a bridge rectifier to me. How did you get to the caps conclusion? And please: improve your handwriting or make a printout.

author: t1d
author_rank: Super Contributor
timestamp: September 10, 2018, 04:40:50 pm
content: Ditto.If you have a diode function, on your multimeter, try probing the pins, with that.

author: Jelcke
author_rank: Contributor
timestamp: September 10, 2018, 05:37:22 pm
content: Thanks for your reply.The handwriting is from the previous owner who made the notes.he was a famous surgeon BTW. Here is an other example.In diode mode I get a voltage drop of 0.7v in any direction and between every pin..... no rectifier I thinkresistance1-2 = 0.65K4-3 = 0.65K1-3 = 565 ohm2-4 =567 ohmI have four variations of this device.ca4 14 600 76-22ca4 14 600 76-08ca4 4.5 600 76-19ca4 3.5 600 76-34

author: 6PTsocket
author_rank: Regular Contributor
timestamp: September 13, 2018, 04:31:57 am
content: Kemet, a capacitor manufacturer does have a CA4 series and some have 4 leads but they are not in line and they are tied together in pairs for more secure mounting of a single capacitor. They also make arrays but I combed through the 300 page catalog and could not get a match but that is the closest I got. The 3.5 and 600 sure sounds like a cap. Everything with 4 leads is not a diode bridge.Sent from my SM-G900V using Tapatalk

author: ArthurDent
author_rank: Super Contributor
timestamp: September 13, 2018, 01:48:54 pm
content: The problem with having others give you a guess on what this module does is that the information you've presented doesn't make any sense. In post #3 you say that the resistance between any pins is 650 or 560 ohms so it is unlikely your part has capacitors, if your readings are correct. You draw it as a square assuming any internal component is wired as you show, corner to corner, but you don't really know. The resistance readings you give would indicate a resistor bridge that would have about 605 ohms between these combinations: 1-4,2-3,4-1, and 3-2 and around 375 ohms between any adjacent pins. if the readings 1-2 are different than the readings 2-1 with your meter in diode test mode, there might be diodes inside. It seems strange that they would have molded 4 resistors into a package like this.The 76-xx numbers are date codes. These 1976 date codes are old enough so they might be selenium meter rectifier diodes which could have very high leakage that gets worse with age. circuits like this were often used for meter rectifiers in VOMs.

author: Jelcke
author_rank: Contributor
timestamp: September 13, 2018, 02:19:03 pm
content: Hello,Thanks, I agree that the capacitance is not correct. They are notes from previous owner. Perhaps measured with wrong gear.What remains is the mystery..Last example: CA4 4.5 600 76-19Resistance:1-2 1,2683 Kohm4-3 1,2682 Kohm1-3 159,01 Ohm2-4 157.27 OhmVoltage drop in DIODE mode in any direction1-2 1,136V4-3 1,137v1-3 0,203V2-4 0,201VI put 6v ac @50hz on pin 1-2 and get 1,5dc on 4-3

author: ArthurDent
author_rank: Super Contributor
timestamp: September 13, 2018, 03:10:51 pm
content: Your post #6 doesn't help any. You list resistance of 1-2 as about 1.3K at the top of the list then as about 160 ohms further down. Do you actually mean 1-3 is 159 ??You list voltage drops but show no information or schematic of the test circuit used. What input voltage?? What load?? Where is your reference point??You need to do what I suggested in my previous post instead of just random tests that don't help. If there are diodes inside putting 6VAC across random terminals is a good way to destroy them.

author: Jelcke
author_rank: Contributor
timestamp: September 13, 2018, 03:27:42 pm
content: I updated the last post to 1-3 = 565 ohm. The voltage drops where with my meter in Diode mode. I thought you suggested they where rectifiers hence the experiment with the DC.Let me remind you that this is the beginners forum. So please be clear with what you want me to do.

author: drussell
author_rank: Super Contributor
timestamp: September 13, 2018, 04:14:16 pm
content: This is one of those situations where setting up a simple curve tracer like the old RCA octopus setup can be very handy. Rig it up for very low current and start at a reasonably low voltage since you don't know what's inside and there is potential for damage.

author: Brumby
author_rank: Unknown
timestamp: September 13, 2018, 04:35:45 pm
content: Firstly, for any given type of measurement, there are 12 possible combinations (not just 4) for two terminal measurements on a 4 lead device:1 - 2; 1 - 3; 1 - 4; 2 - 3; 2 - 4 and 3 - 4and their reverse:2 - 1; 3 - 1; 4 - 1; 3 - 2; 4 - 2 and 4 - 3This covers the six permutations of the 4 leads and the two polarities for each.So, for a resistance check, I would be interested to see those 12 measurements. It might also be interesting to see the 12 results for capacitance as well as the 12 results for diode check.This is where I would start.

author: ArthurDent
author_rank: Super Contributor
timestamp: September 13, 2018, 04:55:56 pm
content: "Let me remind you that this is the beginners forum. So please be clear with what you want me to do."Sorry, I thought I was being clear. I said: "if the readings 1-2 are different than the readings 2-1 with your meter in diode test mode, there might be diodes inside." If that is what you have done in the second part of your test, and your meter actually shows forward voltage drop, it is unlikely there are any diodes inside because .2 volts is way too low. Check out any diode you have with your meter and see what the readings are forward/reverse.Also ignore the date codes because they add nothing to the discussion.The suggestion by drussell is good but that requires you to know what the octopus circuit is and requires a scope so it may not be useful to you.

author: drussell
author_rank: Super Contributor
timestamp: September 13, 2018, 05:32:05 pm
content: Quote from: ArthurDent on September 13, 2018, 04:55:56 pmIndeed, it was my assumption that the OP does not have access to an oscilloscope, so I didn't elaborate further to confuse the discussion. I just wanted to point out that therearepotentially ways of identifying things like this mystery component that may be more insightful than the readings that can be provided by a multimeter in a case like this.Jelcke, do you have access to an oscilloscope? Perhaps an electronics-savvy friend, local school, maker space, etc.?

author: Jelcke
author_rank: Contributor
timestamp: September 13, 2018, 10:29:40 pm
content: Yes, I have a Tektronix 485 / Tekscope 720 / siglent SDS 1102CMl+. + Der EE LCR meter + Multimeters, function generators, Counters , sweep generators etc. etc..I can even hook it up to my AVO 160 tube tester or test the THD or freq. response with my Audio precision system one if you want ;-)BTW My Component identifier only sees the resistance and my transistor tester (Peak atlas DCA pro) sees no device.Second: I have 4 variants of this device and 5 of each so it is not one device that may be broken or such...I will make the RCA octopus.CA4 4.5 600 76-19Resistance:1 - 2 : 1.259K1 - 3 : 160R1 - 4 : 1.265K2 - 1 : 1.265K2 - 3 : 1.259K2 - 4 : 160R3 - 1 : 160R3 - 2 : 1.265K3 - 4 : 1.259K4 - 1 : 1.265K4 - 2 : 160R4 - 3 : 1.259KAnd their reverse resistance is the same.Voltage drop in diode mode (107MVAC) (reverse polarity is the same)1 - 2 : 1.134V1 - 3 : 0.204V1 - 4 : 1.138V2 - 1 : 1.135V2 - 3 : 1.138V2 - 4 : 0.204V3 - 1 : 0.204V3 - 2 : 1.139V3 - 4 : 1.135V4 - 1 : 1.138V4 - 2 : 0.204V4 - 3 : 1.135VCapacitance @ 100kHz1 - 2 : 404nF1 - 3 : 3.76uF1 - 4 : 386nF2 - 1 : 355nF2 - 3 : 3.93uF2 - 4 : 3.42uF3 - 1 : 3.65uF3 - 2 : 3.66nF3 - 4 : 375nF4 - 1 : 378nF4 - 2 : 3.50uF4 - 3 : 345.6nFInductance @ 100kHz1 - 2 : 7.127uH1 - 3 : 0.730uH1 - 4 : 7.054uH2 - 1 : 7.234uH2 - 3 : 6.525uH2 - 4 : 0.647uH3 - 1 : 0.685uH3 - 2 : 6.691uH3 - 4 : 7.055uH4 - 1 : 6.917uH4 - 2 : 0.685uH4 - 3 : 7.057uH

author: ArthurDent
author_rank: Super Contributor
timestamp: September 14, 2018, 01:03:19 am
content: Judging from the physical size of these modules there appears there is no way there could be a nearly 4 uF capacitor inside. You appear to be misinterpreting what is inside even though you seem to have enough equipment to actually figure it out. Good luck.

author: Brumby
author_rank: Unknown
timestamp: September 14, 2018, 03:24:11 am
content: Quote from: ArthurDent on September 14, 2018, 01:03:19 amFor the date code given - I would have to agree.I just mapped out the measurements to see what, if any, sort of a pattern might become apparent. The measurements marked with an asterisk are acopyof the value taken with the test leads reversed - ie. The value against 1 - 2* is a copy of the reading 2 - 1. Likewise the value against 2 - 1* is a copy of the reading 1 - 2.There certainly seems to be some symmetry across all measurement types - with the exception of the capacitance where there are two anomalies (green background). The first could be a documentation error nF/uF ? The second is the departure from the symmetry exhibited in the other measurement types.What does this mean? I can't say I have any idea, but I would be inclined to start trying some active circuit measurements.

author: bitwelder
author_rank: Super Contributor
timestamp: September 15, 2018, 04:10:36 pm
content: Have you tried to apply a (modest) voltage to a pair of pins and measure the voltages on the other two (and then repeat with another pair) ?

author: Brumby
author_rank: Unknown
timestamp: September 16, 2018, 02:28:02 am
content: Quote from: bitwelder on September 15, 2018, 04:10:36 pmThis is one example of an active circuit measurement.One suggestion though: Use a current limiting series resistor when applying voltage.

author: ArthurDent
author_rank: Super Contributor
timestamp: September 16, 2018, 05:39:11 pm
content: There is another thread in 'Projects, Designs, and Technical Stuff' that might shed some light on what a possible problem here might be. Check 'SO.... What Capacitance are your Resistors...?'

author: Jwillis
author_rank: Super Contributor
timestamp: September 17, 2018, 10:02:23 pm
content: All components will exhibit ah inherent resistance ,capacitance and inductance.Even rectifiers and capacitors.Also it will be difficult to clearly understand the measurements because its a closed circuit of 4 diodes.Meaning you get conflicting results because the measurement is taken from both directions of the circuit.Looking at the component I would have to agree with Benta that this is likely a rectifier.Likely a 600v 4amp.The 14 and 3.5 numbers looks like lot numbers with the date code below as someone else described .You can use a low voltage AC signal of no more than 6 volts to the 2 center pins and read the outer pins for a DC voltage .If it is a capacitor array then you should be able to read a slow voltage discharge from any two pins with a resistor in parallel and a DMM.

author: ArthurDent
author_rank: Super Contributor
timestamp: September 18, 2018, 01:36:20 am
content: There are many problems here but the biggest problem is between the chair and the component trying to be identified. None of the information presented so far makes any sense and varies from one post to the next. The readings taken with a meter in diode mode are said to give voltage drops of about .2 volts which isn't likely with any diode made in 1976, or today. The nearly 4 uf readings in a package so small are also impossible. If these were bridge rectifiers they would likely have the 2 sine and the + and - symbol embossed on the part, not 1,2,3,4. The original poster says they have all sorts of equipment but hasn't been able to use any of it to figure out what the parts are despite numerous suggestions.At this point I think a hammer might be the best way to figure what is inside.

author: Jwillis
author_rank: Super Contributor
timestamp: September 18, 2018, 05:20:41 am
content: Considering its age its not impossible that its a germanium bridge rectifier?Wouldn't that explain the low voltage drop?Can be lower than 0.3V Although I've not seen them in this type of package .Could explain why there are no data sheets.Also the pins are not sequential 1-2-4-3 .Odds at the outside and evens at the inside.Most definitely an oddity.Hammer time.

author: MK14
author_rank: Super Contributor
timestamp: September 18, 2018, 05:42:02 am
content: At first I would probably have said a bridge rectifier. But it does not necessarily have the markings to be one, such as a polarity notch, +/-, etc.Could be a 4 pin SIP, DC to DC converter.That could explain the various "strange" component readings, as it would probably have a lot of passive components and a few semiconductors in it. It might also explain why it has 4 numbered pins on it.Example:

author: Jelcke
author_rank: Contributor
timestamp: September 18, 2018, 03:55:36 pm
content: No useful output on any legs when feeding DC or AC.I have used an axe to open this one up.

author: drussell
author_rank: Super Contributor
timestamp: September 18, 2018, 04:04:31 pm
content: I figured by the pin numbering that it was some kind of hybrid module like that but couldn't find any cross-reference with any of those numbers that might shed some light on what the configuration might be.Now you know.Out of curiosity, what are the values of the individual components?

author: MK14
author_rank: Super Contributor
timestamp: September 18, 2018, 05:18:12 pm
content: So some kind of bridge resistor configuration.

author: ArthurDent
author_rank: Super Contributor
timestamp: September 18, 2018, 07:09:24 pm
content: It appears that all 4 components in the modules are film resistors with the green resistors being lower value than the white ones. I suspect that these devices are balanced audio attenuators, or networks, with the green resistors being the input and output termination resistors and the white resistors being the series resistors between the input and output. This would mean 1 & 3 are the input and 2 & 4 are the output, or visa-versa. I’ve provided a link to a reference and if you scan down you will find a drawing of an “O” attenuator and a description further down.http://www.uneeda-audio.com/pads/A guess without being able to personally check out the 4 variations of these modules is that the 3.5, 4.5, and 14 might be attenuation values and the 600 on all 4 versions could mean they are for 600 ohm audio circuits. If the resistance between 1 & 2 and 3 & 4 are higher for the units marked ‘14’ than for the ‘3.5’ and ‘4.5’, that would make sense for them being attenuators. It would also make sense that the numbering sequence is 1,2,4,3. Again, without actually being able to check them out, this is just a guess.