I got idea when I was doing something with DC motors. I wanted to check the current but I was beginning to get angry on digital instrument. So I created DC A-meter that can measure up to 5 A.
This A-meter is very simple. The question is if it can be useful at all? YES! Most cheap digital instruments must not be connected more than 10s in the circuit when we are measuring more than 1 A, but this kind of instrument can be.
All the materials are scraps from other projects (including A-meter).
Used-up time: 1 hour
Step 1: Parts in Tools
Parts used for A-meter:
- Analogue DC A-meter
- 1x black connector
- 1x red connector
- 2x cable boots
Tools used in process:
- 2 mm and 8 mm drill
Step 2: Cutting and Drilling
First I draw sketch of A-meter on housing. Housing had some holes from some old projects.
After sketching, I cut out large hole. I used saw for wood. When I was finished, I had removed all the rough edges with knife. When the large hole was finished, I placed A-meter into hole. I did rough sketch where holes for screw should be. Then I drilled for holes with 2 mm drill.
Holes for connectors were already cut. I just needed to make it bigger so the connectors can fit in. I did that with 8 mm drill.
In the end of this step I fit in A-meter and both connectors.
Step 3: Wiring
I have some wires attached to the A-meter. Because I was in hurry I didn’t change them. Those wires are around 0.75 mm^2. This mean that they can still be good for 5 A at 24 V. So I didn’t bother.
I shorted these wires to right length and then I have attached cable boots. After that I bolted cable boots on connectors. For these actions I used pliers.
Step 4: Finish It Up
When all parts were properly installed, I close the housing. I use acryl mixture to cover left over holes.
And there you have DC A-meter that can measure up to 5A! =)
Step 5: Testing
For testing I have used DC driller. I measured around 200 mA. For comparison, with cheap digital instrument I measured 0.23 A, which is 230 mA. When we compare those two instruments we must count in classes of instruments and that analogue instruments is accurate in the last third of his range.
It is not perfect, but for me that is fair enough!