Electronic devices and components, in the terminal stages which employ electromagnetic relays, to this day has not lost its relevance among radio Amateurs. Despite competition from thyristors and optoelectronic devices, circuits control the load devices remain niche where the solenoid is indispensable. Their popularity among radio Amateurs due to the low cost, versatility (multiple groups of contacts), high reliability, compactness of the housing. Therefore, the use of low-power relay becomes the optimal solution when switching electronic components medium to high power high-voltage electric circuits (in the limited dimensions of the devices).
For starters, take a look at models manufactured by a domestic low-power relays. They are divided into three types.
1.With one group of switching contacts
RES 10 (passport RS4.524.302, RS4.504.314, RS4.504.319), RES 15 (passport RS4.591….003 006, ХП4.591…. 010 014), RES 34 (passport RS4.524.372, RS4.524.376), RES 49 (passport RS4.569.000, RS4.569.423, 424) and others.
2.With two groups of switching contacts
RES 6 (passport RF0.452.10…104), RES 9 (passport RS4.524.200…201, RS4.524.209, RS4.524.213), RES 37 (passport RF4.510.064, RF4.510.072), RES 47 (passport RF4.500.408, RF4.500.417), RES 48 (passport RS4.590.201, RS4.590.207, RS4.590.213, RS4.590.218), RES 54 (ХП4.500.010…011), and others.
3.With four groups of changeover contacts: RES 22 (passport RF4.500.131, RF4.500.163, RF4.500.225, RF4.500.231), RES 32 (passport RF4.500.342…343, RF4.500.354…355) and others.
All of these electromagnetic relays are rated for a trigger voltage of 10 to 20 V. you Can include in the electric circuit and with slightly higher voltage (to 30 V) in series with the relay coil, connect a limiting resistor of MLT type with a capacity of at least 1 watt. However, if voltage more than 30 V, the application of such relays is impractical: increasing total current, limiting resistor generates a large amount of thermal energy in the initial moment of applying voltage to the coil of power surge may bring the relay down.
For all the electromagnetic relays used in electrical circuits, the defining parameters are the resistance of the winding, the actuating current and the number of contact groups. These settings are specified in the passport to each device.