Other Projects > 5 Volt Power Regulator

Why this project?
Finished 5V Regulator

This is a circuit that I use quite a bit making robots. Very few of the chips like 9 volts. But, most will tolerate 5 volts. After completing my last project, I realized that I used it quite a bit and should write it up. I am using a 9 volt battery for this application, but you could, just as easily, hook into the 12 volt wiring in your car.

Note and Disclaimer: Soldering irons get hot. If you solder enough, or not carefully enough, you will get burned. Oh, and wear eye protection!

There are two basic shapes of 5v regulators. They perform the same function. The TO-92 is suitable for most low amperage functions. The TO-220 is for higher amperage devices and it has a built in heat sink. You can use either for our purposes. Normally, I would use the TO-92 package for my bots because it is smaller an lighter in weight. But I have a lot of the TO-220s that I salavaged and I am a fan of recycling, I am going to use the TO-220 which I removed from an old dvd player (see the E-Salavage DVD Player article).

The main thing to keep in mind is the pinout of the device you are using. Check it twice BEFORE you start soldering. Otherwise you won't get 5v out of it. You will get a little over 7805 Pin Outs8v and it may get a bit hot. Hooking it up the power to the switch first (9V power in to switch, turning it on applies it to the input of the TO-220) will save power in the long run.

You can also add a LED for a power on indicator. I decided to do this after the fact. Since I am tapping into the 9v before it

The two Types

 gets reduced to 5v, I am going to use a 510 ohm resistor.

With a fresh 9v battery, the output is 5.07v.

 You can find the datasheets for the 78L05 here and the 7805 here.

 

 

Parts
The other parts
Soldered up
Soldered up, before LED was added
Bottom view of switch
Bottom view of switch

Front of Switch

Front of Switch

Soldered up
Soldered up, before LED was added
Top of Assembly
Top of Assembly
LED side view
LED side view
Final test
Final test

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