Two-Tone Audio Generator (T326E)

This 1965 circuit generates 250 to 2,000 Hz tones with quality sine waveform. The power supply is not given and the tubes are of well known types.

IQS360 and IQS360A ProxSense Touch and Proximity Controllers
May 2017 - This proximity and touch controller from Azoteq can control 12 mutual channels and can...
Emergency Light (CB243E)
When the AC Power line fails, the transistors in this circuit are biased to conduce the current to...
LED Indicator LM3909N (CB4555E)
This circuit was obtained from a 1978 Practical Wireless. It causes an LED to flash at a frequency that...