DIY is a portable multimeter smaller than a cigarette box.

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When I first entered this forum, I would like to dedicate all my practical DIY production to everyone, first on the Supermicro Simple Multimeter.
Everyone may have a few pieces, but the ultra-micro multimeter is broken, and it doesn't hurt. (The cost is too low.) This ultra-super multimeter is suitable for emergency use. There is only one equivalent of 1K and another 30V. DC block (changeable voltage block)
Material: 1 shell, 1 small head, 2 resistors, 1 1.5V battery, 2 test leads, 2 jacks or 3 foot switches.
Power-blocking: 1.5V battery string resistance and meter head, change the resistance to straighten the head to the full gear, measure several resistors and mark the position of the hands, when you use it, you can judge the resistance value Blocked. It saves a battery for one year without problems.
Adjust the voltage block: the external voltage string resistance into the meter head, change the resistance is the position of the meter pin, (such as: to do a 25V block, use 5V power to access, adjust the resistance value to make the hands to 1 grid. 2 squares when measuring It is 10V, and 3 is 15V.
As long as you have a smaller head, the player has a small battery and uses a micro 3-pin switch to switch the resistance voltage. You can make a micro-super multimeter that is smaller than half of me.