Forum: General Capacitor Questions & Issues
Today, 03:31 PM
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Replies: 7
Views: 123
Re: 3300µF 450V caps...
In the repair shop one tech would charge caps to 400VDC in the Heathkit and toss them at you yelling "catch!". I let them fall on the ground but a few people got nailed.
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Forum: General Electronics Technical Discussion
Today, 03:29 PM
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Replies: 30
Views: 240
Re: flourescent ballast resistance
I know two-wire tubes are cold-cathode. If you have a HV AC source, like a car ignition coil+555, you can put the HV wire anywhere near the tube and it will ionize and light. BBQ lighter not sure....
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Forum: General Electronics Technical Discussion
Yesterday, 01:32 PM
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Replies: 30
Views: 240
Re: flourescent ballast resistance
Pic shows two wires to the tube and the Osram datasheet (https://www.osram.com/appsj/pdc/pdf.do?cid=GPS01_1027844&vid=PP_EUROPE_Europe_eCat&lid=EN&mpid=ZMP_58994) showed two and said DULUX S is CFL....
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Forum: General Capacitor Questions & Issues
Yesterday, 12:19 PM
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Replies: 7
Views: 123
Re: 3300µF 450V caps...
You can do the math but the energy to lift up a person a foot off the ground, is stored in one cap. How far a commie would launch... they're full of so much hot air lol.
I don't short...
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Forum: General Electronics Technical Discussion
Yesterday, 11:15 AM
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Replies: 30
Views: 240
Re: flourescent ballast resistance
Oh it's cold cathode? Then it's just a matter of the starter/ballast making a kV pulse. Sometimes holding the tube or having it next to grounded sheet metal helps it ionize at lower voltages.
There...
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Forum: General Electronics Technical Discussion
06-28-2022, 03:28 PM
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Replies: 30
Views: 240
Re: flourescent ballast resistance
That seems reasonable. You can check if there is a ground fault, winding shorted to case.
If the overall startup current is too low I think the starter will just sit there trying to get the...
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Forum: General Electronics Technical Discussion
06-28-2022, 02:10 PM
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Replies: 30
Views: 240
Re: flourescent ballast resistance
I would measure its inductance. F14T5 is 14W 0.265A lamp current, need around 900ohms impedance, so 148R from the coil and maybe ~2.5H is needed. Using 240VAC and 40V tube drop for rough math.
Does...
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Forum: Troubleshooting Game Consoles & Other Weird Devices
06-28-2022, 10:46 AM
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Replies: 17
Views: 260
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Forum: General Electronics Technical Discussion
06-28-2022, 10:42 AM
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Replies: 18
Views: 231
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Forum: Equipment Usage, Soldering, Techniques, and Reviews
06-27-2022, 11:11 PM
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Replies: 10
Views: 343
Re: Short finder
All that is missing is a PCB layout? It's not that complicated, it's just people wanting changes and complaining etc. that takes away all the fun....
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Forum: General Electronics Technical Discussion
06-27-2022, 05:56 PM
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Replies: 4
Views: 124
Re: Microwave advise please
Last to check is for open filament wiring at the connector/feed-through capacitors or for a bad connection there, or inside the can at the EMI chokes. Magnetron filament is low voltage, high current...
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Forum: General Electronics Technical Discussion
06-27-2022, 04:06 AM
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Replies: 52
Views: 2,697
Re: Fixing a multimeter based on VC9805 schematic
Display shows 1___ with those readings?
Pin 40 COM voltage is too low, it needs to be at least 1V above V-. On the schematic it would be QC4,QC3 to check- that would short COM below 1V. On your...
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Forum: General Electronics Technical Discussion
06-26-2022, 11:20 AM
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Replies: 18
Views: 231
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Forum: Equipment Usage, Soldering, Techniques, and Reviews
06-26-2022, 11:17 AM
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Replies: 9
Views: 189
Re: Buy a Agilent U1242A or Fluke 179 DMM?
I'm repairing three old American-made multimeters, but I might have maxxed out at having 10 lol I've got no Flukes, just HP, Beckman, Wavetek.
I hate Taiwan-built multimeters, either they blow up...
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Forum: General Electronics Technical Discussion
06-25-2022, 02:11 PM
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Replies: 11
Views: 188
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Forum: General Electronics Technical Discussion
06-25-2022, 10:29 AM
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Replies: 11
Views: 188
Re: Conversion of Anolog Voltmeter into Ammeter
Your test setup looks good, I think there is a poor connection or maybe a switch is inside the meter so you must press it down to take a reading.
Usually panel meter specs are two things - the coil...
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Forum: General Electronics Technical Discussion
06-24-2022, 09:54 PM
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Replies: 52
Views: 2,697
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Forum: General Electronics Technical Discussion
06-24-2022, 12:41 PM
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Replies: 18
Views: 813
Re: Using car key fob as generic remote control
Check the RXB6 pinout, it has an enable pin 6 which floats high to enable data, not power save.
Some of those 433MHz RX modules have extremely weak data output 10uA (!) so a low value pullup or LED...
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Forum: Troubleshooting Game Consoles & Other Weird Devices
06-24-2022, 12:26 PM
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Replies: 17
Views: 260
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Forum: Troubleshooting Game Consoles & Other Weird Devices
06-23-2022, 07:17 PM
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Replies: 17
Views: 260
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Forum: Equipment Usage, Soldering, Techniques, and Reviews
06-18-2022, 10:39 PM
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Replies: 10
Views: 343
Re: Short finder
I think you'd need the compliance voltage-limited to say 0.2V to not damage anything. That pretty much rules out the LM317, have to use an op-amp and power transistor.
I also do well with a good...
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Forum: General Electronics Technical Discussion
06-18-2022, 10:34 PM
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Replies: 4
Views: 166
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Forum: General Electronics Technical Discussion
06-17-2022, 04:51 PM
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Replies: 52
Views: 2,697
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