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
IRON-VULCANIZER
With the help of electric iron, you can quickly and safely fix Velocimetry, warmers, Pasika recorders, inflatable toys, etc. m by putting patches and connecting them vulcanized. The...
THIS CAR
Maximum simplicity, minimum weight and dimensions at optimum amenities available materials, components and assemblies, simplified (not at the expense of quality) manufacturing technology...
