To obtain a small offset and a high rejection, the four mixer entries must have a 200 Ω impedance. Those impedances are obtained with resistors R5-R8, which belong to the voltage divider from every ...

The pulse width of the trigger signal must be a minimum of 2.5 miliseconds. The voltage supply is between 9 volts and 20 volts. The circuit consumes about 2 mA or less. If the circuit is apllied as a ...