Reed switch / calculator counter

[Meowy]

How many cycles per second can the reed switch / calculator counter support? Is the limit on the reed switch or the calculator?

I am hoping to max out my winder at several hundred RPM, so I would need to be able to count at a rate of approaching ~10 cycles per second. Is this attainable with this solution?

[trevorus]

You may check out a pedometer for counting the windings. Hooking a reed switch in place of it's step sensor is pretty easy, and I figure it would be faster than a calculator.

I also found a pickup winding program too, with a counter. http://pickups.myonlinesite.com/programs.php

[David King]

I think the standard procedure with a calculator is to use it as a decade counter. Count one every ten turns.

[Wrnchbndr]

I just built a winder using a reed switch and it has no problem clocking every rotation up to 2100 rpm using the counter that I have. The post is in the tools/pickup winders section and at the link I give the part#s and sources of supply. Using an o-scope, the pulse train coming from the reed switch is clean as a whistle. What I found important was to be able to adjust the air gap between the magnet and the reed switch. While watching it on a scope, you find that there is a sweetspot where everything just works great. There are no drop outs or bouncing. Even without an o-scope, its not hard to find the sweet spot and I believe that not having the adjustable air gap would most likely lead to it not working. The chances of getting it right so it reads at high velocity with a non-adjustable gap are minimal.

[chevalij]

the trick with the reed switch is position. Too close and it bounces, too far away no reading. Also, when I used a reed switch, I found placing it at approx. a 45 degree angle to the magnet travel helped. You get a little more time for it to react to the magnet without it affecting the other half of the switch. I now use an optical switch thats freaking fast (probably good for about 10k) and more stable than a reed switch. You can build one for about $30 with a Red Lion cub counter from ebay. If anyone is interested, I'll put up a parts list and schematic in a few days.

[black_labb]

i use the reed switch and calculator idea, and have put it on a gear that counts every 5th turn (its a lathe, so it wasnt an issue finding a gear on the thing that counts the right no.)

its a simple way to do it, but does have its limitations with speed, which can be fixed by using a slower gear on the system, if possible