Motor Speed Regulator Kit
This kit contains parts to build a unidirectional, variable speed, electric motor driver. The kit is based on a 555 timer and includes a motor and a battery box. Once again the kit was purchased from AliExpress. The following screen shot of the AliExpress advert also shows the included parts.
Instructions, in chinese, were provided with the kit. Google Lens and Google Translate came to my rescue in producing a passable English language translation. That was very helpful since I did need the instructions on this occasion.
Once I'd clarified a couple of issues using the instructions the kit went together quite easily. It was important to solder the small components first because access to some of them is difficult once the larger components are in place. The only thing I'm not happy about is that I got one of the blue terminals badly aligned - my fault, not the kit's. Here's the completed main board, along with battery box, motor and potentiometer knob & fitting nut:
I first tested the board with the provided motor and my bench power supply. One issue was that the voltage rating printed on the PCB next to the power input terminals states 6V. However, the supplied battery box takes just 3 AA 1.5V cells, supplying a total of 4.5V. As a result I tested the circuit with the bench supply set to 4.5V.
Everything worked, but with the speed control pot as far counter-clockwise as it would go the motor was whining and trying to turn. The instructions point out that the motor start speed is set using the trim pot (to be found to the left of the speed control pot in the photos). I ended up turing this pot a long way counter-clockwise before the motor was silent and still. Once that adjustment was made everything worked just fine. So I connected the battery box in place of the bench power supply and installed some batteries I found lying around:
All in all, I enjoyed building this kit. And it's going to find a practical use at some point. So thumbs up for this one.
Finally, here's a video of the finished kit in use, running on batteries: