Forum: General Electronics Technical Discussion
Yesterday, 01:48 PM
|
|
Replies: 7
Views: 86
Re: bad cap cause fuse to blow?
The microwave oven capacitor can go low value or open-circuit (blown pressure switch), either gives no/weak cooking.
The capacitor can also have a ground fault. If if arcs internally to the can that...
|
|
Forum: General Electronics Technical Discussion
05-26-2022, 11:05 PM
|
|
Replies: 7
Views: 158
|
|
Forum: Troubleshooting Audio Equipment
05-26-2022, 11:00 PM
|
|
Replies: 18
Views: 228
|
|
Forum: Troubleshooting Audio Equipment
05-26-2022, 02:22 PM
|
|
Replies: 18
Views: 228
Re: Dummy loads for amplifier fault finding
At 1kW power level, for any significant length of time you need a cooling fan or a water/oil bath.
The resistor you linked to (https://www.aliexpress.com/item/1005001694646924.html) has to be...
|
|
Forum: General Electronics Technical Discussion
05-25-2022, 03:37 PM
|
|
Replies: 7
Views: 158
|
|
Forum: General Electronics Technical Discussion
05-25-2022, 03:10 PM
|
|
Replies: 10
Views: 144
Re: Component identification
OP you are lucky it did not arc and make a big black mess. Those Rifa safety capacitors crack and short out with age, causing equipment damage and bonfires. Never use them, I don't know why Kemet...
|
|
Forum: Troubleshooting Audio Equipment
05-25-2022, 03:04 PM
|
|
Replies: 18
Views: 228
Re: Dummy loads for amplifier fault finding
How many gigawatts? How many ohms? How long to reach 88MPH?
Appliance heating elements can be used as long as the heat can be dissipated. An empty kettle, or space heater with no fan, is no good for...
|
|
Forum: General Electronics Technical Discussion
05-22-2022, 08:04 PM
|
|
Replies: 8
Views: 173
|
|
Forum: General Electronics Technical Discussion
05-21-2022, 09:21 PM
|
|
Replies: 8
Views: 173
|
|
Forum: Equipment Usage, Soldering, Techniques, and Reviews
05-21-2022, 09:14 PM
|
|
Replies: 6
Views: 448
Re: Hot air station - 858D opinions?
My 110V 858D+ came with a 220V heater. So you get about 200W only. It actually works OK on the usual smaller SMT but I would say heat is not enough for big stuff.
220V heater is 805W at 240VAC, 71.6...
|
|
Forum: Troubleshooting Game Consoles & Other Weird Devices
05-20-2022, 03:11 PM
|
|
Replies: 3
Views: 122
Re: Thermador Oven Controler Dim display
OMG price gouging for these boards is criminal!
Repair your oven control board by replacing $5 worth of capacitors! Just to stop from throwing the whole appliance away.
Oven/Range Control Board -...
|
|
Forum: Troubleshooting Game Consoles & Other Weird Devices
05-19-2022, 06:54 PM
|
|
Replies: 4
Views: 174
Re: Jenn Air Wall Oven Dim LCD
OP you seem to have a wrong model number, it should be JJW2730 for 30" wall oven. It's like a space ship, lots of electronics.
A dim fluorescent VFD display on older oven control boards is usually...
|
|
Forum: Troubleshooting Game Consoles & Other Weird Devices
05-19-2022, 02:36 PM
|
|
Replies: 3
Views: 122
Re: Thermador Oven Controler Dim display
OP, can you switch off power and try using a small mirror? Also, measure the diameter of them. They come in standard sizes like 8, 10, 12.5mm etc.
edit: also a cellphone camera pic can work, just...
|
|
Forum: General Capacitor Questions & Issues
05-17-2022, 01:32 PM
|
|
Replies: 7
Views: 143
|
|
Forum: Troubleshooting Game Consoles & Other Weird Devices
05-14-2022, 01:08 PM
|
|
Replies: 31
Views: 1,784
Re: Agilent U1253B OLED display failed
That's great, using an MCU as a protocol translator to keep new displays compatible and stick it to Keysight. He totally redesigned the power section.
I think the first board fits U1273A. OLED TV's...
|
|
Forum: General Electronics Technical Discussion
05-13-2022, 05:45 AM
|
|
Replies: 39
Views: 1,212
Re: TIP120 Question
IRF620 (https://www.vishay.com/docs/91027/irf620.pdf) switches in nanoseconds, not microseconds. FAST.
I've tried building SMPS using Darlingtons and it was basically terrible to get past even 30kHz...
|
|
Forum: General Electronics Technical Discussion
05-12-2022, 09:03 PM
|
|
Replies: 35
Views: 562
Re: Line filter question
I checked the safety standards and basic insulation hi-pot test is about 1,500VAC for 1 minute.
Double-insulated 3,000VAC, they just doubled the test voltage for ungrounded equipment.
This...
|
|
Forum: General Electronics Technical Discussion
05-12-2022, 12:00 PM
|
|
Replies: 39
Views: 1,212
Re: TIP120 Question
TIP120 switching times are about 0.5usec on and ~3usec off with a -ve voltage drive to force it off faster. If you're not doing that or saturating it, it's much slower I would say up to 10usec to...
|
|
Forum: General Electronics Technical Discussion
05-12-2022, 11:34 AM
|
|
Replies: 35
Views: 562
Re: Line filter question
The power supply you built I thought is a linear one with a big power transformer, so it possibly has low leakage current and can be run with no ground if you're confident about the wiring and...
|
|
Forum: General Electronics Technical Discussion
05-11-2022, 01:42 PM
|
|
Replies: 35
Views: 562
Re: Line filter question
Those LED CC sources are setup to regulate above 16V, I guess they wanted the LEDs dim below that.
OP is connecting outlet PE with Neutral which is really not a good way to go. Because it's...
|
|
Forum: Troubleshooting Power Supplies and Power Supply Design
05-10-2022, 07:58 PM
|
|
Replies: 17
Views: 449
Re: Miele cat and dog hs05 vacuum power supply
I missed it - what was wrong with the Miele vacuum cleaner speed control board? The schematic is nice work.
R1 is across triac gate-MT1 and just keeps it off, lowers its sensitivity with high dV/dt....
|
|
Forum: General Electronics Technical Discussion
05-10-2022, 07:53 PM
|
|
Replies: 35
Views: 562
Re: Line filter question
It ran too hot, SOT-23 transistor dissipates 0.25W at 2mA/240VAC and 1/2 wave.
Almost all of these outlet/socket testers are just lamps in a delta configuration. Although the Fluke has a PIC MCU.
|
|
Forum: General Electronics Technical Discussion
05-10-2022, 03:25 PM
|
|
Replies: 35
Views: 562
Re: Line filter question
Neons are fine, I have one tester like that but they need at least 60-75V to light up.
That's too much for a lamp to earth-ground, you could have 50V and nothin' lit (w/120VAC mains here).
Modern...
|
|
Forum: General Electronics Technical Discussion
05-10-2022, 01:45 PM
|
|
Replies: 35
Views: 562
Re: Line filter question
240VAC Outlet tester (http://www.marcspages.co.uk/pq/4511.htm) using three neon lamps. I'd have to think how to make an LED version, and just leave it plugged in all the time.
For my workbench I use...
|
|
Forum: General Electronics Technical Discussion
05-09-2022, 03:50 PM
|
|
Replies: 35
Views: 562
Re: Line filter question
I think it's a problem if a group of outlets are grounded together but end up hazardous live because there is no ground in the first place and Y-caps or worse are providing leakage currents. If...
|
