This circuit is from a 1980s Motorola documentation. The circuit can be set to fire from 60 to 120 V DC or from 42 to 84 V AC. The circuit has a forehead button that activates an indicator lamp.
This amplifier has a few Watt output, using old transistors. The speaker is 45 ohms, but with...
This circuit was found in an 80's Electronic Design. It amplifies TTL fast signals for a coaxial...
This circuit uses a Norton operational amplifier to generate 1 kHz pulses with a 1 to 60...