Amplifier relaySometimes we need to activate a relay (relay), with a very weak signal, for example a source that provides about 5µA, this is the role we propose the following circuit.
With just a signal of 5 µA. can be turned over who should have a coil voltage power line, for example if we are going to use a source of 12 volt CD, this must be the voltage that supports the coil.
The transistors Q1 and Q2 are in Darlington configuration, when a signal is present at the entrance through R1 serving as limiting, will result in Q1 and this in turn activates a Q2, motivating this by current flow through K1, This closing its contacts and thus activating the load on them. The mission of D1 is to avoid false contacts.
Q1, Q2: BC548
Resistors 1/4 watt:
R1: 1.5 M
R2: 10 k
K1: relays (relay relay) to 12 volts.
pcb expensive components of the amp relay
pcb expensive components print