Published by Philips in 1965 documentation, the sensor for this circuit is a common LDR. The transistors are general-purpose types from the time, only TR3 is a power type according to the load.
Using a ceramic resonator, it is possible to vary the frequency between 4.9 MHz and 5 MHz. The...
The circuit in the figure can be used to trigger a triac or even a comparator in a project that...
This is a circuit with two switches, one turns on and the other turns off for DC loads using SCR....