1 channel power relay module with adjustable timing cycle explained | HCW-M421

Use of 1 channel power relay module with adjustable timing cycle - HCW M421

In this tutorial,  we will understand the usage of delay timer relays and different modes of operation. 

Delay timer relays are used when a sequential flow of control over devices is needed, in triggering alarms, repeating tasks in loops, signalling etc. In fact your washing machines/dish washer uses it to handle cycles and to delay cycle start.

I am going to use HCW-M421 module for this tutorial. It has majorly 4 modes of operation with few modes having sub modes as well. 

Front view

Back View

It has a built in 5v mini usb power input which is very handy. It also has a 6-30V and GND for powering the relay in case mini usb is not being used. It has a trigger and GND_T to be connected from a micro controller or a trigger generator. In this example, i will be using 3.3v power module as trigger generator. It has 3 output terminals  (NO,COM,NC) similar to a 1 channel relay module as explained in this tutorial. It has 4 input buttons, SET, UP and DOWN are used to set mode of relay and set values for OP (operation time), CL (Clear line) and LOP (number of cycles, --- is unlimited cycles). It also has a emergency stop button which is used during configurations to change decimal point to increase or decrease precision of relay.

Now lets get into the modes of operation. This relay has a total of 4 modes. P-1, P-2, P-3 and P-4

P-1 Mode

This mode is used when relay have to be triggered upon an input. It has 3 sub modes. P-1.1, P-1.2, P-1.3

Configuration is same for all 3 sub modes with  variation in re-trigger behaviour.

P-1.1

Upon trigger input, relay is on for OP time and any input re-trigger while relay is on is ignored.

Usage: Turn on a device upon trigger for until OP time expires. Useful in applications where preset time is known.

P-1.2

Upon trigger input, relay is on for OP time and any input re-trigger while relay is on results in re-clocking. 

Usage: Turn on device for min OP time with re-triggered allowed. Calling Bells at home!!!

P-1.3

Upon trigger input, relay is on for OP time and any input re-trigger while relay is on results in relay turning off.

Usage: Turn on the device until a re-trigger or initial set timer expires. Some coffee vending machines... 

We will use the 5v mini usb to power the relay and use 3.3v power module to trigger input.

P-2 Mode

Upon trigger input, relay will start timing and relay will turn on after CL time and stay on till OP time expires. 

Usage: For introducing delays in powering on devices like motor, alarms, high voltage sequence devices.

P-1.1

P-1.2, P-1.3 and P-2

P-3 Mode

This mode has 2 sub modes P-3.1 and P-3.2

This mode introduces LOP where you can specify the number of cycles the actions
needs to be performed on relay.

P-3.1

Upon trigger input, relay will start timing and relay will turn on after CL time and stay on till OP time expires. This continues for the number of cycles set. --- on LOP means unlimited times.

Usage: Used for repetitive actions on trigger. Watering plants at set time in breaks for 2-3 times.

P-3.2

No trigger input needed, relay will start timing and relay will turn on after CL time and stay on till OP time expires. This continues for the number of cycles set. --- on LOP means unlimited times.

Usage: Used for repetitive actions like hydrophonics where same action is carried out indefinitely. 

P-4 Mode

Upon Trigger, relay holds the signal until OP expires. If a retrigger happens before OP expires clock is reset. This is similar to P-1.2 with a minor difference when re-triggering continuously. When the trigger is being re-triggered continuously the relay will be on and timer will be reset and will hold until trigger is off. It then starts OP time and relay is turned off after OP time expires.

Usage: Used to clean noise or work with jitter signals.

This is a powerful relay with low cost.  With this we will conclude all relay based tutorials.