When you repair a computer power supply unit or perform a modification, you need to constantly measure the voltage. It is also sometimes necessary to measure the resistance of the output voltages. I decided to assemble the adapter between the power supply and the multimeter. With such a device, hands will always be free and work will be faster. Also, this unit can be used to power low-power devices. The current is limited by the operating current of the switch.
The circuit of the device is simple and it can not be assembled. The input voltage comes to the 20-pin connector, and the output voltage is removed from the terminals. All voltages are switched by a jack switch. There is an indication of the power supply of the computer. The indication LED is powered by 5 Volt duty.The power supply of the computer is started by a switch.
Making the switch
The device is mounted in any suitable case I will do the case myself. I will make it out of PVC plastic. Plastic scored from advertisers, trimming which are discarded.
Cut out the necessary parts of plastic and glue with super glue. It turns out such a letter "O". You also need to cut the front and back panels.
Connects the power supply of the computer to the connector for 20 contacts. I dropped it from the old motherboard.
Switching the output voltage will be flashing switch PG-3. If it is possible to take the switch to 6 positions, then it's wonderful. I have 11 positions, but that is, that is.There was also a pen on the switch.
You can turn on the power supply with any switch. I have a switch from the old TV set.
On the front panel, drill holes for the wafer switch. Diameter is 8 mm.
The connection indicator will be an LED. To limit the current to the LED, you need a resistor, you need 150 Ohms.
Drill the hole for the LED. Diameter 4.5 mm, under the LED 5 mm. So it will be more densely installed.
Cut a hole for the connector in the side wall.
Drill a hole for the switch from the top of the case.The diameter of 12 mm. At this stage, I did not decide on the terminals for connecting the multimeter. Therefore, painted the body in black color, drill holes later. After the paint has dried, still drilled one hole. The photo shows.
I will use plugs from the SR-A military connector as removable terminals. Immediately soldered to them wires and insulated. The front panel will be glued with super glue, and the back panel will be screwed with small screws. To screw the screws, I glue the substrates of the same plastic as the case. Adhesive for super glue. I attach the front panel.
I still lay off the case andI pass to the scheme. Everything is soldered according to the sketched scheme. It is convenient to connect the connector of the power supply and unplug the colors of the wires accordingly. Soldering places must be insulated.
I uncoil the switch according to the scheme. Everything is simple and accessible.
Soldered the LED and switch. Now you can install everything in the case.
Plug the glue on the super glue with soda. Excellent glue is obtained, almost like epoxy.
Screw the back wall and get a great design.
The test switches
Connect the multimeter. Turn on the switch.We control the output voltage of the computer power supply. During the build process, I redid the sequence. So it seemed to me more convenient. The duty mode is duplicated. The LED lights up and the last position shows 5 volts.