2-1157 test load design for 24 V

[steves7839]

I've built a test load for 24VDC using 2 auto 1157 bulbs in series. The cold ohm measurement looking into the load is under 1 ohm. Should I add some resistance?
Thanks for reading!
Steve

[tom66]

Re: 2-1157 test load design for 24 V

As soon as the bulbs warm up, their resistance will increase.
The cold resistance may be too low to allow the power supply to start. If so, additional resistance may be necessary.

[budm]

Re: 2-1157 test load design for 24 V

You can put NTC Thermistor is series, also use the low beam filament instead of the high beam.

[Alastair E]

Re: 2-1157 test load design for 24 V

These are 'side-tail Brake-lights not Headlights there Bud....

Only on rare occasions would one need to check the current drawn from an LCD backlight psu....
Normally, If its producing 24V when its supposed to, then it'll work in the set, so no need for bulb tests for 'em....

2 sec to black is nearly always the Bl board or tubes issues.

[budm]

Re: 2-1157 test load design for 24 V

These are 'side-tail Brake-lights not Headlights there Bud....

Only on rare occasions would one need to check the current drawn from an LCD backlight psu....
Normally, If its producing 24V when its supposed to, then it'll work in the set, so no need for bulb tests for 'em....

2 sec to black is nearly always the Bl board or tubes issues.

It has two filaments one for low brightness (running lights), one for high brightness (when brake is applied), I use them for testing also.
http://s807.photobucket.com/user/bud...?sort=3&page=1

http://s807.photobucket.com/user/bud...?sort=3&page=2

Some power supply will not handle high inrush and it will go into shutdown.