Voltase hobby

This is a simple Electronic Solid State Stepping Switch Circuit Diagram. Solid is one of the four fundamental states of matter. It is characterized by structural rigidity and resistance to changes of shape or volume. In electrical controls, a stepping switch , also known as a stepping relay, is an electromechanical device which allows an input connection to be connected to one of a number of possible output connections, under the control of a series of electrical pulses. 

 

This schema was designed to make switching of a 48-channel mobile transceiver safe to operate while mobile. The oscillators allow for single-stepping or a scanning function. The scan facility allows for stepping through all 48 channels to check for occupancy or otherwise, and each output is indicated with an LED and labeled accordingly, so at-a-glance indication is possible.With full scope of this schema it is possible to scan 256 channels and by adding more 4 to 16 line encoders etc. you could switch to any required number.

This is a Simple Sound Activated Tape Switch Circuit Diagram. This schema can cause a cassette recorder to automatically tum on and record when a sound or noise is present. Another use, is when the sound-activated switch is used to tum on a cassette player so that it operates as a burglar-alarm detector and sounder. Op amps Ula and Ulb are connected in tandem to amplify the sounds picked up by the detector`s mike. 

The amplified audio voltage, output at pin 7 of Ulb, is fed to a voltage`doubler schema, consisting of Dl and D2. The elevated voltage from the doubler schema is input to the positive input of op amp Ulc, which is operating as a simple comparator schema.Sound-activated-tape-switch The other input of Ulc is connected to a voltage divider that sets the switching point for the de signal voltage, to turn on when the signal level is greater than about 1.5 V. As the comparator switches on, its output at pin 8 becomes positive and supplies a forward bias to tum on D3 and Ql, which in tum, starts the recorder. 

The rc combination of C4/R9 sets the cassette`s run time after the input sound has ceased, preventing the recorder from chopping-up or turning-off between closely spaced sounds or words picked up by the mike. The delay time is roughly 6 to 8 seconds. Rll sets the schema`s gain. Connect a low-impedance cassette mike to the amplifier`s input, and connect the output of Ql to the cassette`s remote input or to the internal input and set the recorder to the record position. Talk and adjust the amplifier`s gain with Rll for the desired sensitivity.