Lighting Transformer Problem

[danbates]

Hello People,

I've got a piece of club lighting gear for a party a while back, it broke, and upon opening the thing it turned out the circuit board providing the correct power for the bulb had snapped from it's mounting and short-cicuited on the metal chassis, blowing several components..

I've decided, if I can, to replace the whole board with a single high power transformer, I'm wondering if this is wise. From what I see written on the bulb and board, what it's doing is transforming the voltage from 230VAC to 24VAC, then 24VDC I think. The bulb is halogen, 24V 250W.

Can I simply ditch the elaborate board of zener diodes and power transistors for a single rated toroidal power transformer?

Can a 24VDC halogen bulb with AC?

Would much appreciate any advice.

Regards,
Dan

 

[Sid723]

The circuit board and electronic parts are there to provide current and voltage at a high frequency. As long as the lamp is operated at a high frequency current, the transformer needed can be a small ferrite type. This is probably designed to fit in a smaller case. If you were to use a regular 50/60 Hertz transformer it would require a much larger transformer and may not fit in the original case. I would try to repair the original circuit if possible.

 

[jerryg50]

The circuit that is driving the lamp is a high power high frequency switching supply that is designed with the proper current and voltage regulation for the lamp.

It is not a simple supply using simple components to run the lamp. If it was so simple the manufacture would have done it that way in the first place!

Servicing these supplies can be very complicated. The components used are critical, and when these blow there is usually a lot of damage. Normally the manufactures of these types of fixtures will sell a complete new replacement circuit board, or the complete fixture only.

250 Watts at 24 Volts is a lot of power. This would require a supply that can have a continuous load of more than 10 Amps. The supply maximum rating would have to be a good percentage greater than the average load. Most manufactures use about 50% over-rating for the maximum current loading.

Call the manufacture or their rep and see if you can order a new board.


Jerry G.

Hello People,

I've got a piece of club lighting gear for a party a while back, it broke, and upon opening the thing it turned out the circuit board providing the correct power for the bulb had snapped from it's mounting and short-cicuited on the metal chassis, blowing several components..

I've decided, if I can, to replace the whole board with a single high power transformer, I'm wondering if this is wise. From what I see written on the bulb and board, what it's doing is transforming the voltage from 230VAC to 24VAC, then 24VDC I think. The bulb is halogen, 24V 250W.

Can I simply ditch the elaborate board of zener diodes and power transistors for a single rated toroidal power transformer?

Can a 24VDC halogen bulb with AC?

Would much appreciate any advice.

Regards,
Dan

 

[danbates]

components

Thanks for replies so far, I can see the reason for a high frequency, high power circuit. The manufacturer Spektronic is unreachable so I'll repair the circuit myself.

Like you said Jerry, there's a lot of damage, two capacitors blown and all four transistors desoldered it seems.. Looking at the thing the heat dissipation seems poorly designed, so I'll fix the transistors onto the sink better too.

I'm trying to decode a capacitor value, it says 2E684J on it.. any ideas?

Dan

 

[(*steve*)]

I'm trying to decode a capacitor value, it says 2E684J on it.. any ideas?

Probably 0.68 uF (otherwise written as 680 nF)

 

[danbates]

I've tried figuring out another part number.
It says MSP 103 on it and is an inductor I think. On the board it has a small inductor symbol and the letters RT.

Would I be right in guessing it was a 10mH inductor?

Cheers,
Dan