I found a silver plated, steam lcomoitve shaped piggy bank. Its called a "Puff Puff" bank on the box, but it does not puff smoke. So Ive set out to make it do so. I have the smoke unit, light, restart timer, and power supply already worked out. The restart timer is triggered by a momentary pushbutton switch, once the switch is pushed, it turns on power to the smoke unit and light for one minute. I planned to replace the pushbutton switch with a photoresistor and a laser, so that when a coin was dropped in a laser would be blocked, causing the photresistor to become conductive and close the cicuit, acting just like the switch. This was great until I found out that photoresistors become conducticve when they are exposed to light, not when it is blocked. I need a way of causing a coin to momentarily complete a circuit, without using the coin as a conductor (hence the laser idea).
Please help, I am confused on how to accomplish this.
Please help, I am confused on how to accomplish this.
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