Fault signalling circuit

Fault signalling circuit: The present circuit was developed to make it possible for different sensors to be added to an existing alarm installation. These sensors may be gas or smoke detectors, door switches, 1 infra-red detectors, and others. In quiescent operation, the level at all 44 inputs must be zero. When the relevant sensor is[…]

Read more

Triangular-signal generator

Pulse duration modulators 19%; a perfect triangular signal, that is, one that is absolutely symmetrical with straight sides. Any deviation from this results in distortion. The design is the usual rectangular-triangular oscillator. A Schmitt trigger converts a triangular wave into a rectangular one. which is used to continuously charge and discharge a capacitor via current[…]

Read more

Field-strength meter

Field-strength meter: The unit discussed here indicates, by means of a chain of LEDs, in logarithmetic ratios the strength of an electric field surrounding the unit. The inputs signal across the conducting discs is applied to the non-inverting input of IC1. The amplification of IC1, A = R4/P1. In the prototype, P1 was set at[…]

Read more
1 2 3