175w to 70w MH reduction circuit

[tastydog]

What can I do to take a 175w ballast and reduce it to a 70w ballast?

I have a brand new 175w ballast I got for a frag trade and I need to run a 70w bulb on it instead of the 175w. I know you can't just run a 70w bulb on it because the voltages and amperes are different.

Would a carefully selected transformer placed on the output line of the ballast before the lamp get the job done? I think this would still draw 175w on my electric bill though. Is there a way to modify the ballast itself?

Brandon

 

[sirreal63]

This would be the safest reduction circuit you can get.

http://www.aquacave.com/vossloh-schwabe-70w-brmetal-halide-electronicbr-ballast-2297.html

Or put a 175 watt bulb and reflector over it...much safer and better light production.

 

[tastydog]

Whatever. I will post when I find a real answer.

 

[IJayC1]

Wow.....some people are ungrateful arent they

 

[sirreal63]

I don't consider it ungrateful...just a lack of understanding on what he wants to do.

Lamp Rated Current Nominal Voltage
175-watt MH 1.5 Amps 132 Volts
70-watt MH 0.9 Amps 85 Volts

Reducing 1.5 amps and 132 volts to .9 amps and 85 volts will require more electricity than than the 175 watt ballast, and will end up costing more than using the 70 watt ballast or the 175 watt bulb and fixture. It will also create a greater chance of failure of the ballast and is kind of a pointless exercise. Yes, you can probably do this...but the questions is why would you?

 

[NatureNerd]

As an electrical engineer, I completely agree with the above suggestion to buy the right ballast. The cost and hazard is not worth it to try to use the 175W ballast. It is, of course, possible, just not practical. The cost of a suitable transformer and chassis would exceed a new ballast.

 

[tastydog]

Okay. I was hoping to find a way to do it cheaper than that. Looking around at different transformers I can find some that are not very expensive. I have not pulled it apart to take a look so that I can understand how to modify this ballast to achieve the desired voltage and amperes output. I just figured if I searched hard enough I could find the parts to modify the thing for less than 80 bucks. Apparently I was wrong.

Thanks for the responses and letting me know what is probably the case. I am still going to research it a bit more. I was just trying to figure out how to use the 175w ballast since it did not cost me anything. Maybe someone would trade me a 175w for a 70w *shrugg*

sirreal63: I did think you were just being dismissive. I understand your reason for the first post now. Thank you for clarifying and not taking it personally.

Brandon