Abstract: A circuit for monitoring the voltage across a sensing resistor in series with a load, wherein two reference currents are generated, each dependent both on temperature and on the voltage on a power supply line, which voltage is also temperature-dependent and exhibits a temperature coefficient of such a sense and magnitude that the changes in a reference current due directly to changes in temperatures are substantially offset by the changes in that reference current due to changes in the voltage on its power supply line, which changes are in turn due to the same changes in temperature.

Abstract: In a keyboard for an electronic circuit having a striker on each key formed of electronic material which is conductive or carries a conductor and which is moved downwardly towards a fixed conductor assembly to provide capacitive coupling, it is found that electrostatic charges can be generated by operation of a key which give spurious outputs. The present invention provides constructions for reducing the effects of such charges.