A variable power supply with adjustable voltage and current outputs made with the L200 regulator. Using the versatile L200 voltage regulator, this power supply has independent voltage and current limits. The mains transformer has a 12volt, 2 amp rated secondary, the primary winding should equal the...
Audio Booster Circuit
Small and portable unit, Can be built on a veroboard The amplifiers gain is nominally 20 dB. Its frequency response is determined primarily by the value of just a few components-primarily C1 and R1. The values of the schematic diagram provide a response of ±3.0 dB from about 120 Hz to better than 20,000...
Hydrophone Booster Amplifier HA2
The HP series Hydrophone Booster Amplifier (HA2) amplifies low-level hydrophone signals over a wide range of frequencies. It has a minimum gain of 25dB and an input and output impedance of 50Ω. The HA2 is designed for use with either Precision Acoustics membrane hydrophone or Precision Acoustics HP...
Luggage Security System
While traveling by a train or bus, we generally lock our luggage using a chain-and-lock arrangement. But, still we are under tension, apprehending that somebody may cut the chain and steal our luggage. Here is a simple circuit to alarm you when somebody tries to cut the chain. Transistor T1 enables...
Audio Level Threshold Control
This circuit was originally designed for use in detecting discharges from individual neurons, where the infrequent discharges are difficult to separate from dominant background noise. It may also prove useful in other applications that need to detect infrequent low-level audio signals against a noisy...
