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.
Recommend to read
HOLSTER FOR TOOL
Often need to work at heights or in cramped conditions when you need to have all the necessary tools and if I look in one motion, to get or put him in his place. Just a soft case or...
WINDER-SORTER
The experimental winnowing machine-sorter is designed for selection work. The winnowing machine body is made of pine beams, to which the side plywood walls are attached. The beams are...
