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MR220,1,2 Miniature Relay Card Series

The MR220 seriese is a miniature relay board with terminals for the Input & Output. The relay is a dual changeover. The relay contacts are rated at 2Amps. Ideal for switching equipment of a different voltage to the circuit voltage.
 
Left Terminal T1
(1) Common 
(2) Normally Closed NC
(3) Normally Open NC                                                                         
Right Terminal T2
(1) Common
(2) Normally Closed NC
(3) Normally Open NC
Terminal T3
0v = Negative or 0V volts
C1 = Positive volts
C2 = Not Connected

MR220
MR221
MR222
MR220    5v Specification
Voltage Switch On range       3.75 to 8.0 vDC
Coil Resistance (Ohms)         125 x (1+/-10%)
Contact Resistance (Ohms)  50 max at 0.1v
Contact Material                 AgNi + Au plated
Contact Rating   1A @ 125vAC, 3A @ 30vDC
Max Switching Voltage                30vDC
Operating Time                         7 ms max

MR221   12v Specification
Voltage Switch On range      9.0 to 18.0 vDC
Coil Resistance (Ohms)         450 x (1+/-10%)
Contact Resistance (Ohms)   50 max at 0.1v
Contact Material                  AgNi + Au plated
Contact Rating     1A @ 125vAC, 3A @ 30vDC
Max Switching Voltage               120vDC
Operating Time                         7 ms max

MR222         24v Specification
Voltage Switch On range     18.0 to 35.0 vDC
Coil Resistance (Ohms)       1600 x (1+/-10%)
Contact Resistance (Ohms)    50 max at 0.1v
Contact Material                  AgNi + Au plated
Contact Rating     1A @ 125vAC, 3A @ 30vDC
Max Switching Voltage               120vDC
Operating Time                          7 ms max

Here the Circuit is used to control a water pump and Panel Indicators. The Float switch is used to power the relay, when the float switch is activated the relay switches on, which switches the pump On and changes the Indicators from Red to Green. Can be used for Water Butts, Ponds, Pools, Bilges, Sumps, Fish Tanks,  in fact anywhere a liquid needs to be pumped. Pumps can be any voltage AC or DC.
The Input via the Float switch must be the same as the Relay you have selected 5vdc,12vdc, or 24vdc.

T1 Terminals could be used to switch ON & OFF an indicator back at the control Panel.


2) Model Rail Simple Set of Points with Signals on both tracks.
In this set up direction of travel is from left to right, so we need to control signal A and signal B at the same time so they
 have the correct aspect at all times. The magnet SW933 is glued to the moving arm of the point assembly. The reed switch SW926, SW927 or SW929 is placed within 10mm of the arm when the points are set to straight through, thereby activating  the relay.  Not too close otherwise it will remain activated when the points change.