This proximity sensor was found in a 90s Popular Electronics. The base is a PLL567 that operates at around 100 kHz. The circuit operates by capacitance sensing.
This circuit from an old Argentine publication from the 1970s uses a power transistor to obtain an...
The amplifier presented with the TDA2003 can provide a power of up to 10 W (rms) in a load of 2...
This power supply provides a12 V stabilized output. The transistor must be provided with a good...