| David Farber <farberbear.unspam@aol.com>: Aug 19 07:39PM -0700 This Schumacher 1042A-PE battery charger stopped functioning today. It seemed to work for a little while but when I noticed the car battery's voltage wasn't slowly increasing after performing a 2 amp charge for 2 hours, I checked the voltage at the charger's cables and it was 0 volts. The continuity of the switches and cables were all good. I did find a power semiconductor which I could not identify, BTW70-200SN. I looked in an old ECG cross-reference book and the closest match was for a BTW69-800 which is an SCR in a TO-218 package. The package seems to match the device I'm looking for. I made some measurements with my Simpson 464 DVM on the 2k ohm scale. Pins 1 and 3 measure 38 ohms regardless of test lead polarity. All other combinations of continuity measure open circuit. In circuit, pins 1 and 2 are soldered together. Any idea what this component is or how to test it? Thanks for your reply. David Farber Los Osos, CA |
| Phil Allison <pallison49@gmail.com>: Aug 19 09:08PM -0700 David Farber wrote: ============= > regardless of test lead polarity. All other combinations of continuity > measure open circuit. In circuit, pins 1 and 2 are soldered together. > Any idea what this component is or how to test it? ** Could be an SCR maybe............. With a 1A, current limited, DC supply of about 12 V, + on the anode - on the cathode, apply a brief pulse of +50mA at +1.5V to the gate with - on the cathode as well. The 12 volt supply should the be clamped at about +1.2V. You 38 ohm readings are normal. ..... Phil |
| Jeff Liebermann <jeffl@cruzio.com>: Aug 19 10:25PM -0700 On Fri, 19 Aug 2022 19:39:03 -0700, David Farber >This Schumacher 1042A-PE battery charger... Are you sure about that model number? Methinks that SE-1052A-PE is more likely. -- Jeff Liebermann jeffl@cruzio.com PO Box 272 http://www.LearnByDestroying.com Ben Lomond CA 95005-0272 Skype: JeffLiebermann AE6KS 831-336-2558 |
| David Farber <farberbear.unspam@aol.com>: Aug 19 11:30PM -0700 On 8/19/2022 10:25 PM, Jeff Liebermann wrote: >> This Schumacher 1042A-PE battery charger... > Are you sure about that model number? Methinks that SE-1052A-PE is > more likely. Youthinks correctly! It is a 1052A. Thanks for your reply. -- David Farber Los Osos, CA |
| Jeff Liebermann <jeffl@cruzio.com>: Aug 20 12:09AM -0700 On Fri, 19 Aug 2022 23:30:27 -0700, David Farber >> Are you sure about that model number? Methinks that SE-1052A-PE is >> more likely. >Youthinks correctly! It is a 1052A. Unfortunately, that didn't help when looking for information using Google search. I couldn't find anything on the SE-1052A-PE except the owners manual. No schematics or articles on repairing it. No photos of the inside. <http://powertool.manualsonline.com/manuals/mfg/schumacher/se_1012d_se_1052.html> Notice that the user manual covers a range of models which probably share similar circuitry. Try searching for the other models. SE-1010-2, SE-1012D, SE-1052, SE-1250 -- Jeff Liebermann jeffl@cruzio.com PO Box 272 http://www.LearnByDestroying.com Ben Lomond CA 95005-0272 Skype: JeffLiebermann AE6KS 831-336-2558 |
| Jeff Liebermann <jeffl@cruzio.com>: Aug 20 12:28AM -0700 On Sat, 20 Aug 2022 00:09:28 -0700, Jeff Liebermann <jeffl@cruzio.com> wrote: >Notice that the user manual covers a range of models which probably >share similar circuitry. Try searching for the other models. >SE-1010-2, SE-1012D, SE-1052, SE-1250 Bingo, except that there's no SCR in the schematic. <https://www.fixya.com/support/t25414948-wiring_diagram_switch_se_1052> <https://www.fixya.com/support/t7882270-looking_wirring_diagram> Kinda looks like just the PCB wiring and not the complete unit. This is from a different charger (SE-1275A) that MIGHT have the same wiring. How close are the drawing and schematic to what you have? -- Jeff Liebermann jeffl@cruzio.com PO Box 272 http://www.LearnByDestroying.com Ben Lomond CA 95005-0272 Skype: JeffLiebermann AE6KS 831-336-2558 |
| David Farber <farberbear.unspam@aol.com>: Aug 20 08:38AM -0700 On 8/19/2022 9:08 PM, Phil Allison wrote: > ..... Phil Hi Phil, Looks like I have to make another correction. Jeff pointed out the model number I posted was wrong, the correct model is 1052A-PE The other correction is that pins 1 and 2 of the "SCR" are NOT soldered together on the pc board. Pin 2 (center pin) is snipped off and the connection is made through the component's heat sink. This is the same heat sink which is electrically common to one end of four discreet (bridge?) diodes. Getting back to the testing of the SCR (if it is an SCR), how do I identify anode, cathode, and gate? Thanks for your reply. -- David Farber Los Osos, CA |
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