turnout (points) control - with or without a computer

with or without a computer turnout (points) control Turnouts (points) are usually controlled remotely by the use of electro-magnetic drives (solenoids) which are operated by short pulses of current. In practice things sometimes go wrong and the pulses of current will cause the solenoids to go literally up in smoke. The electronic drive and power supply described in this article can prevent such disasters. As long as the turnouts in a model railway are remotely controlled by hand, the risk of damage to the solenoid is small: you will note almost immediately whether the coil goes on humming when the voltage has not been switched off in time. Nowadays, it is not too difficult to automate any model railway by a microprocessor. This implies immediately, however, that much more stringent requirements must be met by the turnout control circuits, because the computer cannot hear, see, or smell. This seems an excellent reason to have a critical look at the control of electric turnouts. At ...