This circuit was found in a 73 magazine for radio amateurs of the 90s. The circuit uses two types of indicators, the diodes are for general use. The power supply is 5 V.
We found the circuit of this Japanese transistorized commercial receiver in a documentation from...
In the figure we have a constant current source for Shape Memory Alloy or (Nitinol). The...
We found this circuit in the Texas Instruments opto-electronics manual. The button resets and the...