When the phone rings, a high-powered incandescent light comes on. This circuit can be interesting to obtain the remote call warning or to assist the hearing impaired.
We found this circuit in a November 1970 Radio Electronics. It uses a PUT or programmable...
We found this circuit in a technical documentation from the 1970s. It converts low frequency...
This modulated siren was found in the December 1974 issue of Radio Electronics magazine. A higher...