Dim Bulb Schematic

[AGT]

See lots of you tubers who use the standard filament lamps to limit inrush current, anyone got a diagram for this?


It’s normally a switch with test/bypass with lamps in standard batten holders..

[ALAN/ALAN D]

Ref. " to limit inrush current "

Bit more info required on what your trying to do.

[AGT]

Just looking to see when this was a thing, common in electronic repair shops to stop equipment blowing up and releasing magic smoke on switch on.

[AGT]

Like this


https://antiqueradio.org/dimbulb.htm

[ALAN/ALAN D]

If it is old valve equipment your looking to repair.

Quote " As the diagram shows, the dim-bulb tester puts an incandescent light bulb between your radio and the AC power in the wall. This way, if your radio has a short circuit, it will simply light up the bulb instead of damaging itself."

This would cause a lot more damage.

That system would instantly apply full mains voltage to the item. Causing failure in D.C. capacitors by applying high voltage.
The best way to bring valve things back to life is to apply very low D.C. voltages to the circuits. Increasing in steps over a 24 hour period.
A small mains variable voltage transformer feeding a solid state full wave rectifier wired down stream of the internal valve rectifier brings bits back to life.

What things are you looking at trying to repair. ?

[Tinbum]

Is it for battery inverter start up?

[AGT]

If it is old valve equipment your looking to repair.

Quote " As the diagram shows, the dim-bulb tester puts an incandescent light bulb between your radio and the AC power in the wall. This way, if your radio has a short circuit, it will simply light up the bulb instead of damaging itself."

This would cause a lot more damage.

That system would instantly apply full mains voltage to the item. Causing failure in D.C. capacitors by applying high voltage.
The best way to bring valve things back to life is to apply very low D.C. voltages to the circuits. Increasing in steps over a 24 hour period.
A small mains variable voltage transformer feeding a solid state full wave rectifier wired down stream of the internal valve rectifier brings bits back to life.

What things are you looking at trying to repair. ?

Anything/everything, just planning the repair workshop and trying to get stuff out to figure what power outlets are required

[AGT]

Is it for battery inverter start up?

Generally vintage electronics repair, was just seeing if anyone in here had built one, or had an opinion.

[ALAN/ALAN D]

Something like this on Ebayyy.

https://www.ebay.co.uk/itm/134384632079 ... SwQk9jqcHF

For repair works it needs to be fed from a double wound transformer to isolate it from the grid.

Then the variac transformer out put feeds a full wave bridge rectifier. to allow D.C. voltage to be increased from 0 volts to the equipment operating voltage over time.

[AGT]

If it is old valve equipment your looking to repair.

Quote " As the diagram shows, the dim-bulb tester puts an incandescent light bulb between your radio and the AC power in the wall. This way, if your radio has a short circuit, it will simply light up the bulb instead of damaging itself."

This would cause a lot more damage.

That system would instantly apply full mains voltage to the item. Causing failure in D.C. capacitors by applying high voltage.
The best way to bring valve things back to life is to apply very low D.C. voltages to the circuits. Increasing in steps over a 24 hour period.
A small mains variable voltage transformer feeding a solid state full wave rectifier wired down stream of the internal valve rectifier brings bits back to life.

What things are you looking at trying to repair. ?

Strange as I see lots of you tubers pretty clued up individuals using this type of tester, along with isolation transformer and variac