3055RLE? - Page 1
Forum section: electronics / projects

author: mbear2k
author_rank: Regular Contributor
timestamp: January 21, 2017, 09:41:56 pm
content: Hello all - I'm working on a small board that controls a player piano pedal damper solenoid. The board has a TO-220 transistor that blew up (physically). It seems to be used as a switch to apply power (40v I believe) directly to a fairly large solenoid that pushes the damper pedal. The only other part on the board that I can find bad is a shorted 1N4001 diode.The transistor pieces I was able to reassemble enough to make out what I believe is 3055RLE. I'm not finding any data sheets for that specifically, so wonder if anyone is familiar with this part number? Maybe the same as a TIP3055?There are no schematics - and this is 1992 technology... But I am contacting the manufacturer to see what they will share.Follow-on question. Assuming the worst and there is other damage, I've been probing around to see what I can find in-circuit. The small fuse is okay. When measuring resistance between VCC and Ground on all chips, I read 168 ohms. This look low?Appreciate any input.

author: mbear2k
author_rank: Regular Contributor
timestamp: January 22, 2017, 02:12:43 pm
content: I've found that they use the same transistor for all the key solenoids. Below is a pic of one undamaged. Looking at the circuit a little, I'm wondering if this is a FET?It appears to be made by Harris?

author: Buriedcode
author_rank: Super Contributor
timestamp: January 22, 2017, 02:34:42 pm
content: I would have thought its a typical 3055 (TIP3055) NPN power transistor.You could check if its an FET by checking the diode drop from base to emitter (pin 1 to pin 3), and base to collector (pin 1 to pin 2) on the transistors that are functioning.

author: Andy Watson
author_rank: Super Contributor
timestamp: January 22, 2017, 03:53:14 pm
content: Quote from: mbear2k on January 21, 2017, 09:41:56 pmThe transistor looks like it met a rather violent end - like a short circuit load. Was the 1N4001 the catch diode across the solenoid?Given the age and lack of obvious biasing arrangement my thoughts would be towards it being a mosfet - possibly RFP3055 LE. The LE suffix is important - it means that it's a logic-level device.http://datasheet.datasheetarchive.com/originals/scans/Scans-006/Scans-00123519.pdf

author: SeanB
author_rank: Super Contributor
timestamp: January 22, 2017, 04:06:47 pm
content: Most likely a MOSFET, and I bet the current through the coil is around 3A or so, so the first thing to fail was the 1N4001, which then let the mosfet experience the high voltage turn off pulses that killed it, or it went short circuit and did a similar thing.Trace the gate drive back, it probably goes to one of the chips, and that likely is also dead. Replace the 1N4001 diode with a more robust type, probably a 1N5404, though the leads likely will not fit the board, so you will have to either use pins to mount it, or use a diode in a TO220 package instead, one with a 100V 10A rating, which probably will not need heatsinking.

author: mbear2k
author_rank: Regular Contributor
timestamp: January 22, 2017, 04:12:25 pm
content: Excellent input! I've drawn a very crude drawing of part of the circuit. Disregard the 100uf cap - it is part of the main supply filtering for the board.So the 7406 is probably also toast...?

author: Andy Watson
author_rank: Super Contributor
timestamp: January 22, 2017, 04:21:46 pm
content: Quote from: mbear2k on January 22, 2017, 04:12:25 pmPossibly. Without replacing the transistor you could power-up the board and check for a sensible signal from the 7406.

author: SeanB
author_rank: Super Contributor
timestamp: January 22, 2017, 04:45:48 pm
content: Before doing that use a DMM in diode check on the 7406 and see if pin 8/10 has a short to ground or 5V, or if there is a diode like action from those pins to ground. Short, time to replace, if the diodes are fine then it probably survived, though having 40V applied to the chip output likely did cook it if the output was low at the time.However your diagram is missing the pull up resistor, which probably is the 470R resistor there, going to 5V. Weird thing is those chips are 40V capable on the output, but on the supply side not so much...... Datasheet says 30V, but many will be fine with 50V, some even go to 60V with low leakage, but 30V is guaranteed with every die out of the fab, otherwise it is the bog standard 5V open collector rating device.

author: Andy Watson
author_rank: Super Contributor
timestamp: January 22, 2017, 05:06:24 pm
content: Quote from: SeanB on January 22, 2017, 04:45:48 pmCurious indeed! Perhaps it's an old design in which they've just substituted a logic-level drive mosfet? The photo of the multichannel board looks as though the mosfets are driven directly from the GALs.

author: mbear2k
author_rank: Regular Contributor
timestamp: January 22, 2017, 05:13:23 pm
content: Someone above mentioned "The LE suffix is important - it means that it's a logic-level device."So I did the diode check.VCC to pins 8, 9, 10 and 11 each gave me a chirp. Switching polarity of my meter leads gave me the same results.Gnd to pins 8 and 9 each gave me a short.Gnd to pins 10 and 11 each gave me a chirp.I meant to mention, I did check the 470 ohm resistor again and it is in fact going to ground.

author: SeanB
author_rank: Super Contributor
timestamp: January 22, 2017, 05:16:22 pm
content: It's dead Jim, Dead.

author: mbear2k
author_rank: Regular Contributor
timestamp: January 22, 2017, 05:59:34 pm
content: Update... my eyes are getting old. Should have seen this from the top. Removed the 7406 and here's what I found. Also, pin 10 goes to a resistor pack - which I suspect is the pull-up mentioned. Still sorting it out.

author: Andy Watson
author_rank: Super Contributor
timestamp: January 22, 2017, 06:28:04 pm
content: Quote from: SeanB on January 22, 2017, 05:16:22 pmVery !

author: mbear2k
author_rank: Regular Contributor
timestamp: January 22, 2017, 06:58:13 pm
content: Ok - installed a socket and checked the resistor pack. The common end is tied to V+. All sections read 1k.And that has me started on a parts list... DM7406LN up first. What do you guys think of the RFP12N06RLE for a MOSFET replacement? The RFP3055LE mentioned by Andy seems discontinued. There is also the NTE2987?And for the diode. Any suggestions for a 1N5404 spec in a TO-220 package? I do have a small pile of IR 8TQ08D 8 amp Schottky Rectifiers.One more question - and I have no real data at this point to support, but believe the voltage is 40v to the solenoid based on reading on other same-make systems.I read 6 ohms DCR across the pedal solenoid. I imagine I could rig up a current limited DC power supply to test, but not sure I have anything that big. Does 6 ohms DCR seem reasonable?

author: Kleinstein
author_rank: Super Contributor
timestamp: January 22, 2017, 07:32:19 pm
content: A fast diode, like a schottky can be a good idea. A slow diode could cause extra stress to the MOSFET, if the current is not back to zero before the MOSFET switches on again. I don't think you need a TO220 case if the old one was just an 1N400x. So an UF540x or SB350 (3 A schottky diode) should be well good enough. Even an UF4001 should work.

author: SeanB
author_rank: Super Contributor
timestamp: January 22, 2017, 09:44:58 pm
content: Youi do need a 5A or better diode, and in general most 5A or higher diodes in circular packages have thick legs, which is why I suggested a TO220 part as it will have thin legs, plus will fit the pinout. 6R for the coil is around right, around 6A of pull in current, and the logic level mosfet will do this with 5v of drive and run cool, and the diode will have enough thermal mass to handle the spikes.Originally the circuit was underspecced, the designers forgot that the catch diode has to handle at least the same current the pass transistor is carrying at switch off, and the energy it has to dissipate is that stored in the coil inductance. Needs a big diode for a high current, not a 1N400x diode like used here for long term reliability.

author: mbear2k
author_rank: Regular Contributor
timestamp: January 22, 2017, 09:49:58 pm
content: It's interesting that all the diodes for the remaining solenoids on the other driver boards appear to be bigger in diameter. I can't quite read what they are though. And all the other solenoids are about half the physical size of the damper pedal solenoid.I think I'll go with the 8TQ08D 8 amp Schottky Rectifier I have at hand.http://pdf1.alldatasheet.com/datasheet-pdf/view/250464/VISHAY/8TQ080.html

author: SeanB
author_rank: Super Contributor
timestamp: January 22, 2017, 10:04:47 pm
content: That will work there, nice part and will fit the footprint as well for the 1N4004 with only a little bending of the leads. 8A and 80V, good enough.

author: mbear2k
author_rank: Regular Contributor
timestamp: January 23, 2017, 06:54:07 pm
content: I got a note from someone that has worked in design with various manufacturers and said that what I had specifically is a "Harris RFD3055RLE FET". I've ordered a FQP30N06L 60V LOGIC N-Channel MOSFET to try.http://cdn.sparkfun.com/datasheets/Components/General/FQP30N06L.pdf

author: Andy Watson
author_rank: Super Contributor
timestamp: January 23, 2017, 07:07:23 pm
content: Quote from: mbear2k on January 23, 2017, 06:54:07 pmThe datasheet that I linked above is for that device. It may not be important in this application but the original device has built-in zeners to clamp the gate voltage.

author: mbear2k
author_rank: Regular Contributor
timestamp: January 23, 2017, 07:17:00 pm
content: Good point - I did also get a 'quote' for the following:Part: RFP3055RLEMan: HARRISQty: 5 (min)Unit Price: $ 3.25Extended: 16.25CONDITION: New

author: mbear2k
author_rank: Regular Contributor
timestamp: January 25, 2017, 01:44:40 pm
content: I found a great source for the RFP30N06LE. I found Gerber Electronics in Massachusetts have about 400+ in stock and were very nice about selling a small quantity. These should be here this week and I can move forward.