# HomeWork Board Rev B Special Instructions

## Vdd - Limited Current Budget

The BASIC Stamp HomeWork Board Rev B’s voltage regulator supplies current to the embedded BASIC Stamp, certain circuits built on the breadboard and connected to I/O pins, and any devices drawing current from the Vdd sockets. The current budget for the Board of Education Rev B board’s voltage regulator is 50 mA. Most devices featured in Stamps in Class texts only draw a few extra milliamps of current and will work fine when powered by the Board of Education Rev B board’s Vdd Pins. However, there are a few exceptions, including servos, pumps, and heating elements. These devices should not be connected to Vdd, or it could damage the board’s voltage regulator. Instead, these higher current devices should be connected to Vin. The voltage supplied to Vin should in turn be limited to a level that is compatible with the device (servo, pump, heating element).