This is the 3D print bed heat controller I am going to show you how to make.
Step 1: Schematic
I found a good circuit for a 555 PWM controller and modified it.
Here is the part list:
1. 555 Timer you can get from Radio Shack
2. IRF8714 This is a MOSFET so handle it carefully it is static sensitive. Its used in my 3D printer for heating the hot end and also in other boards that have built in controls for heated bed.
3. 50K pot The one I used has a long shaft. I had to compensate for that with the 3d printed housing.
4. 1k resistor 1/4 watt
5. 47 Ohm resistor 1/4 watt
6 Two 1N4148 diodes These I had lying around but you can easily locate them at any online store such as Digikey or Mouser.
7. Two 100n These are 100 nano farads the part will have the numbers 104 which is 10 to the -4th power. (.1 PF)
8. One 470uF electrolytic cap. (I didn't have this one on my circuit as I was testing it out but its necessary for the output to be smoother where the voltage does not ramp up and down.
Step 2: Circuit Board
If I had thought of taking photos I would have during construction. I will be making another more advanced and will take snapshots for that one.
This circuit is crude and is my prototype.
Also this will work for anything 12v as long as there is no feedback or reverse voltage on its output.
Also I mentioned that the 470uF cap was not installed. This was so I can test the circuit. The circuit works and I will be adding the component to do another test again.
Step 3: 3D Printed Case
This I had printed out and already made prior to creating this Instructable.
I will try to create a 3D print instructable later