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MULTI-CHANNEL PROGRAMMABLE TIMER

by Noel Rios

Start ý Circuit Description ý Checking and Troubleshooting ý Setting Up the Device ý Sources and PDF

SETTING UP THE DEVICE

After powering up, the LCD should display "Timer V1.0" and will start displaying the time. Usually, a new DS1287 has its oscillator turned off, so you will see that the time is stopped. To set the clock, press the Adjust key, and the hour field will start blinking. To move to the minute setting, press the Select button, and the minute field will blink. While in each field, press the Up button to increment the value, and press the Down button to decrement the value. Pressing Adjust again will bring you to the main screen, or the clock with an asterisk after the time.

To scroll through the channels, press the Select button while in the main screen or Clock mode. It will then display the on and off time (in hour and minutes). To adjust the on and off times, press the Adjust button, and the hour of the on time will blink. To move to the minute setting, press the Select button. To move to the hour setting of the off time, press the Select button again. Pressing Adjust once more will bring you to the Scroll Channels mode.

You will then be able to scroll through channels 0 to 7 by pressing the Up or Down buttons to move back and forth between them. Pressing the Select button once more will bring you back to the Clock mode. It is important to remember that you must be in the Clock mode, and not in the Adjust mode or scrolling through the channels, for the timer to control the devices plugged into it.

Note that pressing Reset will turn on or off all devices in a short time. So, the Reset button is a good way to shut off all the channels at once. Also, in a power failure, on return of power, the devices on all channels must be set on again for safety reasons.

TIME TO GO

There are many uses for the multi-channel programmable timer, and it is only limited to the imagination of the user. The circuit currently designed is for four outlets, but you can expand it to eight if you have eight solid-state relays. Although some provide a supervisory circuit and some safety features are included in the software, this device is not recommended in cases where a catastrophic event will occur if the circuit board ceases to function.

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