Harry Dalek wrote:Klaas Robers wrote:For my disc monitor I used a DC motor from a video disc player. Nice and strong. It has a magnetic speed pick up, with a small magnetic ring having 18 pulses per revolution. So I had to invent something difficult to match the 18 pulses per frame with the 32 (31) from the CD signal. It took me more than one year to come to a reliable and still simple enough system.
Yes i to used one ,that one on the drum monitor but never used the Ac pulse i have another in my shed i might scrap to use in the future and i have 2 other small ones that do the same thing ...pulses per turn i need to test if i ever use them .
Did you make use of the large neon laser ?It is easiest to start with two identical sync systems, e.g. 32 per revolution with or without one missing. Then the 'only" thing you have to do is see that the pulses come in at the same rate and at the same moments.
Thats true thats easiest even for me to work out!
I am going to take Garys advice and buy the laser printer for the next encoder (my wife had trouble with the new printer last night ended up she hadn't had the usb plugged in but gave me an excuse to mention the laser printer idea which she liked ) cheaper than buying the ink cartridges for this HP/
But in your case Harry it's not so difficult. Klaas had to work out a way of getting it to work with different pulses per frame as it had to work with an NBTVA format signal. With your camera you are generating the pulse train with some kind of oscillator so you can make it anything you want, so you can just match what's coming out of the motor pulse generator.
For instance, if you had what Klaas had, 18 pulses per revolution your oscillator would be set at 18 x 12.5 = 225 Hz - when the speed controller locks the 2 signals the disk will be rotating at 12.5 frames a second or 750 rpm.
I am not saying you should do that by the way, only that you CAN.
It might be a fun experiment someday.
BTW, before you buy a laser printer see if you can get a test print out to take home first - that way you can make doubly sure it is IR absorbing.