5 VDC Sensor Input from Vdd?

Mooneyguy

Do I need to configure a regulated 5 VDC voltage supply, or can I simply use the Basic Stamp 2 Vdd 5V to run a sensor that requires a 5 VDC input with a typical input current of 3 mA? The only thing else being used on the Vdd 5V line is a Tach switch that connects to the VDD which is used when the sensor is turned on. The tach switch is used to store a sensor data point. The sensor accuracy is .25% of span, the output is proportional to the input voltage.

Mike Green

Yes, you can use the Stamp's built-in 5V regulator to provide a little bit of power for external devices. It's rated at 50mA output which has to include the amount of power used by the Stamp itself. Typically this is less than 10mA. Remember that any current drawn from an I/O pin counts against this (like LEDs). There are also heat issues. I'd keep Vin to well under 9V if you're going to draw close to the 50mA limit. It's best to use a Vin of 6V or greater and less than 8V (4 or 5 alkaline cells or 5 or 6 NiMH cells).

Mooneyguy

Thanks Mike. Thanks also for the reminder of the LEDs as I do have one of those running too.