I am experiencing noise and voltage drops when a pager motor is turned on and off via a PWM signal from the IC. After about 2 days of continuous operation it is frying the IC.
I am looking for guidance on how to isolate the IC from the motor so that the voltage fluctuations that occur when the motor starts & stops don’t affect the IC.
I’ve attached 2 images:
- breadboard view
The sketch on the IC is basically an analog version of the Blink example.
The minimum requirements for this project are:
- It must run off of a 3V coin cell battery, and no more than two 3V coin cell batteries
- It must use an IC, I am using an ATTiny85
- The motor must be no bigger than a Pager motor
Ideally, I would like to run with two 3V coin cell batteries; one for the IC to pump the transistor & one to drive the motor via transistor.
If I run this sketch with an LED instead of a motor it will last for a little over one week.
Any suggestions on how to isolate the motor from the IC? Or, “Well, there’s your problem…”
Here is the BOM on the breadboard:
D1 Rectifier Diode (1N4001)
M1 DC Motor (Pager Motor)
Q1 NPN-Transistor (PN2222A)
R1 10k Resistor
VCC1 3V Coin Cell