Strömförsörjning arduino
A power supply is unquestionably an absolutely necessary equipment for any electronics lab or anyone who wants to do electronics projects, especially a variable power supply. In this tutorial I'll show you how I built an LM linear positive regulator based variable V (V to input voltageV actually) power supply. A power supply is unquestionably an absolutely necessary equipment for any electronics lab or anyone who wants to do electronics projects, especially a variable power supply.
In this tutorial I'll show you how I built an LM linear positive regulator based variable 1. The power supply doesn't use any transformer instead it reduces constant input voltage in the range of V to many different voltages at the output. The schematic will give you an insight on my plan. But it was not designed to generate a PCB file as I usually perfboard for my one off designs. So I didn't care about the component packages.
9 Ways to Power an Arduino (costs, reliability, uses compared)
You have to select proper packages if you want to create a PCB layout. Each of those LMs will reduce the 36V input to programmed voltages. U2 will output a constant 12V, U3 will output a variable voltage and U1 will produce an auxiliary 12V for other 5V and 3. LM can provide output current in excess of 1.
Power Supply LM317
But in this case, with large difference in input and output voltages, LM will have to dissipate the excess power as heat; so much heat. So we use pass elements. Here I've used TIP power transistor as pass element on the positive side. You could use TIP or 2N as pass element on the negative side or the output side. PNP transistors are used as pass elements in low dropout and ultra-low dropout regulators. But they exhibit some output stability issues which can be mitigated by adding capacitors at the output.
The 2W resistors R5, R7 and R9 will produce enough voltage to bias the pass transistors at low currents. The auxiliary 12V output is connected to inputs of three LM ultra-low dropout 5V 1A regulators of which two are used for USB outputs and the other is for front panel output. One of the 5V output is connected to a AMS regulator for 3. So it's a series network of different regulators. The variable output is taken from U3 as shown in the schematic.
I used a 5K potentiometer in series with a 1K pot to have coarse and fine adjustment of output voltage. A DSN DVM tutorial on my website voltmeter module is connected to the variable output to display the voltage at front panel. See the "Wiring" section to see the modifications to be made to the voltmeter module. You can use any other V or A modules without much modifications. Download high resolution PNG image of the schematic here.
I already had all the components with me. So designing the model was easy. I used MDF board of thickness 6 mm and aluminium extrusions angle of size 25 mm and thickness 2 mm. You can download the SketchUp model file using the link below. You're free to download, modify and redistribute this material. Cut the perfboard as per your requirement. Then place and solder components as per the schematic. I didn't make a PCB file for etching.
But you can use the Eagle schematic file below to make a PCB on your own. Otherwise use your ingenuity to plan the placements and routing and solder everything nicely. All the dimensions with which the MDF board, aluminium channels are to be cut, hole dimensions, hole placements and all are in the SketchUp model. Just open the file in SketchUp. I've grouped parts together, so you can easily hide parts of the model and use the Measure tool to measure the dimensions.
All dimensions are in mm or cm. Use 5mm bits for drilling holes. Always check for alignment of holes and other parts to make sure everything will easily match together. Use sand papers to smooth out the surface of MDF and Aluminium channels.