About code locks wrote more than once. However, most of them are difficult to repeat. Design suggested by our Bulgarian friends (the journal “Radio Television Electronics”), devoid of this shortcoming. For opening this lock simply insert the key and complete the circuit with the resistor R1 a certain value (it is mounted in the housing of the key). If the resistance will be different from that specified on the schematic, the relay does not work and the lock will not unlock.
Lock in idle mode (no key) consumes Ocala 16 mA and 24 mA with the key.
Relay — 6V, 20 mA. Transistors V1, V3 — low-power silicon, for example, KT315 with any alphabetic index.
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If the posters or wall Newspapers transferable adhesive you use fonts, for of application, use a homemade tool — a common pin with head ball stuck in the end of a pencil.
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CUBE... Probably not many times I burnt my fingers when soldering resistors, tubular ceramic capacitors and the like in the form of radio parts. Feeling, know, not pleasant, not...
