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Assembly and Operating Instructions for Kits


Using a 10-turn Potentiometer with a Delay Unit


More how-to articles


DIYers have asked if they can replace the 100k pot on the Multi-Trigger 3 (or other delay circuit) with a 10-turn pot in order to provide greater precision in adjusting time intervals. The answer is yes. With a 10-turn pot, the precision is better than 15 microsec/deg. By flipping the Delay Range switch on the Multi-Trigger 3 to the Divide by 10 setting, you divide the precision by another factor of 10.


Unless you already have a 10-turn pot, buying one new will cost at least 10x as much as a 1-turn pot. If you also want a readout dial on the pot, that's another 10x in price. Here are some sources:


10-turn, 100k pot (plastic shaft)

10-turn, 100k pot (metal shaft)

10-turn, 100k pot with turns counting dial


Racquetball collisionWhile I've rarely resorted to using a 10-turn pot, there are some situations where it can be useful. I used one to capture successive images of a racquetball striking a wall. I shot the ball from a specially-constructed slingshot in order to project the ball with predictable speed and position. I wanted to capture a dimple in the ball that occurs over a very short time span during a collision, and the precision of a 10-turn pot allowed me to do that. The animated gif to the right is composed of 24 successive still images taken at quarter of a millisecond time intervals. The individual frames are shown below. The dimple I mentioned is shown at 1.75 ms into the collision.


Racquetball frames









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