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Power supply for little halogen light popped

bushtech

Sep 13, 2016
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Yes, light is burning brightly. measuring current between one leg of resistor and where that leg of the resistor should be soldered in.And this is after the resistor, downstream.
Voltage drop how? between each end of resistor and ground respectively
 

Tha fios agaibh

Aug 11, 2014
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Yes, light is burning brightly.
Voltage drop how?
Yay, way to go Dries.
Just measuring voltage across the resistor.

I can't explain why your not reading any current.
You should see about .25 volts dropped across that 1.5Ω resistor given ~170ma incoming current.

If you discovered how to supply that load at only 14uA, I want to come work for you.
 
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bushtech

Sep 13, 2016
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Between 0.1 and 0.2V measuring over the 2 legs of resistor. My DMM cant read another digit. Could running it through 60W dim bulb tester be causing the low current?
 

73's de Edd

Aug 21, 2015
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Sir bushtech . . . . .

You say . . .
Could it really be drawing 14.5μA
Its possible . . . .in considering that the power oscillator configuration is not starting up with the voltage drop and the current starving , impeded by the presence of the incandescant lamp being placed inline with the AC power input.

The NON lighting of that inline test lamp insertion, was indicative of no MAJOR loads / shorts on the units power components. Which is what you initially wanted to see.
PLUS . . .that is the main consideration for even using the lamp . . . . . considering other circuity might present shorts on initial turn on. Or that your newly installed parts might crash and burn on initial powering up.

To confirm, get your mini AM radio, set to low end of the AM broadcast band, tune off from receiving any station, max the volume.
And this time you DO NOT have the incandescant test lamp in line and you set the radio atop the units LARGE ferrite balun / donut .(Power transformer)
Then you just do a QUICK stab of the AC power plug into the AC receptacle to initially just get power for 666 7/8 milliseconds
The MAIN lamp of your unit should flash or TRY to start a flash on for that instant , and that radio should raise hell in picking up those strongly emitted, multiple, higher harmonics, for that short power up duration. Then plug in the unit if no smoke.

Then you can go back to having the series incandescant lamp being placed inline with the AC power input. Then you listen when you plug in the AC power to see if even a peep comes from the radio this time. If being quiet there is not being enough of an initial inductive "kick" to start up the power oscillator.
Look at the SECOND minor ferrite balun where osc feedback has to occur and you see the VERY minor inductance values being present . . .therefore . . . they are needing a healthy voltage into inductive jolt, to start up initial oscillation.


73's de Edd . . . . .

Tell me . . . . . . .are VEGETARIANS allowed to eat ANIMAL CRACKERS ?

.
 

bushtech

Sep 13, 2016
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Thanks St Edd
I took the bull by the horns, connected the second leg of the resistor, disconnected the dim bulb, took a deep breath and switched on. No smoke:)
Reinstalled the light and we'll see how it goes. I've got extra 13005's and resistors so if it blows this thread will be revisited
Notes:
No fuse installed
Light could be very slightly dimmer than the others
 
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