I have three homemade dc power supplies that I use for general lighting on my ho scale layout. The diagram for the power supply is attached. The power supply is fed from a lionel 1033, which allows me to set the voltage. I use 8 volts for interior lighting, and 12 volts and 15 volts for exterior lighting. The problem is that as I add load, the voltage drops a small but noticeable amount. My question is, can I add a voltage regulator to these power supplies to keep the voltage constant.
thanx CCG
Of course.
All you need is a standard regulator such as this one. They come in various voltage and current ranges.
http://www.radioshack.com/product/index.jsp?productId=2062600
Springfield PA
The LM317 is a adjustable voltage regulator. You need two resistors and a couple caps for a fixed voltage.
I have never tried this with a variable voltage input.
http://www.reuk.co.uk/LM317-Voltage-Calculator.htm
Replace R2 with a 5k potentiometer for a varalble regulatro.
There is a low current LM317 for 200 ma or less.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
The other responders are both correct, and you obviously have the skills to construct a voltage regulator. Just remember that the regulator's maximum output will usually be about 1.5 volts lower than the input. In other words, to get, say, 12v from your regulator, you need to be feeding it 13.5 or even 14v. Your ultimate power source is still going to be delivering lower voltage as the load increases, so your maximum full-load regulated voltage will be 1.5 or even 2 volts less than the voltage delivered from your power source at full load.
Your diode bridge will not work the way it is drawn. Can we assume that it is just drawn wrong and not actually wired that way?
Dave
Lackawanna Route of the Phoebe Snow
Phoebe Vet Your diode bridge will not work the way it is drawn. Can we assume that it is just drawn wrong and not actually wired that way?
I was wondering on how long it would take for someone to notice that issue. Apparently the OP is gone. We never heard anymore from him on any kind of success but I see that fairly often which usually marks a lone wolf.