# 5 Volt voltage Regulator



## T-Man (May 16, 2008)

What you are looking at is a working mock up, that will take track voltage AC or DC reverse current and supply 5 volts DC for the 555 Timer IC. Minimum transformer voltage is always at least 3 volts higher so an 8 volt transformer would be the minimum. It can be found in a Peter Thorne Model RR Kalmbach book or you can see a diagram On Line at http://www.mrollins.com/pwrsp3.html. It is very simple and all parts are Radio Shack Components. It consist of 2 capacitors, voltage regulator and a bridge rectifier.
The motor wires would attach to # 2 and 3 of the bridge rectifier. The positive and negative feed for the IC is to the bottom left.
The set up is for conventional transformers. Application to HO Scale is a challenge due to space considerations.
The metal hole on the regulator is for an attachment for a heat sink. Depending how much the regulator works is proportional to the heat output. 
If you noticed the capacitors have an arrow showing the orientation to the negative side.










Parts
7805 voltage regulator Radio Shack # 276-1770
bridge rectifier 276-1146
capacitor 100 uf 272-1016
capacitor 220 uf 272 1017
capacitor 10 uf 272-1013
For capacitors the 100 or the 220 can be used.
This is the power regulator for the flasher in the Athearn Ho Engine.

Be patient I may edit this over the next few days


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## mcnay55 (Oct 21, 2008)

Hmm. Good idea. Never thought about using the track voltage. Question, how many amps or LED lights say would I be able to attach safety as not to hurt the transformer. I was thinking of using a bonified 5V powersupply seperate from the track.

Thanks.


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## T-Man (May 16, 2008)

According to radio shack specs it's one amp for the regulator. Expect to use some sort of heat sink for it. The 5 volts is to operate the chip. LED can be powered by anything over 3 volts you just need resistance. The LED only draws 20 to 30 milliamps. The motor is using the same power too.


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