Electrical wiring help?

I have two 9 volt batteries, two 9 volt battery holders with a red and black wire coming from them, one switch with two prongs coming out of it and one light bulb. How can i arrange these items so i have two 9 volt batteries powering this one light bulb with a switch in the middle?


Lets assume the bulb is rated at 9v. Then take the two red leads from the holders and twist them together, then take the two black leads and twist them together. Now you have the batteries in parallel. Take the red lead and hook it to one side of the switch, then take the other side of the switch and hook it to one contact of the bulb. Now take the other contact of the bulb and hook it to the black lead and this completes the circuit. If the bulb is rated at 18 volta, then take one of the holders and hook its red lead to the other holders black lead. This will make the batteries in series and you will have 18v. Just make sure the bulb is rated for this, otherwise it will flash and no lighty no mo
If you are trying to power the bulb off of 9v that will last longer by having twice the batteries you would connect the two red wires and two black wires from the batteries together. Take a red to the switch and the black to the large base of the bulb. Take another piece of wire from your other side of switch to the pin on the bulb. You now have a 9v light that will last twice as long. If you bulb can handle 18v then you would connect a red from one battery to a black from the other. The black from the first battery to the base of the bulb and the red from the second battery to the switch. Now your extra piece of wire from the switch to the pin on the bulb. Only do this if your bulb is rated grater than 18v or you will burn the bulb. If you have an LED it will matter which direction you hook it up.
You can physically place the switch where ever you want but the wiring will still be the same.

Share to: