Coin Operated Telescope
designed by David A. Johnson, P.E.
My client owns several coin operated telescopes. Their problem is that the battery needs to be replaced every few months. I needed to design a new circuit to control the shutter. The solenoid used was too power-hungry.
Once the coin was accepted and fell into the coin box, a motor would open the shutter for 2 minutes. After those minutes had elapsed, the motor would reverse direction and close the shutter. The timer would allow only one coin at a time.