I am a big believer in a greener way of life so I reduce reuse recycle and repurpose, to this end I gather many things put out for the garbage, the computers I get my wife likes to rebuild and gives them away to people that can’t afford a computer. The other things I get to repair repurpose or strip for parts.
In this Instructable I am going to repurpose a coffeemaker into a travel alarm clock, when I worked as a truck driver I had this travel alarm clock I bought in a truck stop for $20.oo. It was advertised not to use near a graveyard or it would wake the dead. I went through three of these alarm clocks they had the knack of growing legs and walking off.
I found the coffeemaker while I was helping my friend George make his deliveries, at first I wanted to use the clock circuit for testing LCD displays. Later that week I was visiting my brother and he mentioned he didn’t have an alarm clock and I got a new purpose for the clock circuit.
All the parts I used in this Instructable were salvaged but the battery I bought at the local dollar store making the total cost of construction one day and one dollar.
Step 1: The Coffeemaker
The coffeemaker was a Kenmore ADC coffeemaker; I plugged it in to make sure the clock worked.
Now that I knew the coffeemaker was working I dissembled the coffeemaker from the bottom up by removing all the screws from the base and then the components inside.
There are a few deep screws so you will need a long 12 inch Philips screwdriver.
I keep all the working parts that I may have a use for later.
Step 2: The Clock
There were two circuits in the coffeemaker the clock and control circuit and the power and switching circuit.
There were 4 wires going between the two circuits and a thermal control line to turn off the burner when it was at temperature.
I removed the thermal control wire and tested the clock making sure the running LED light lit up and the relay tripped.
Step 3: Testing
With my multimeter I found out what each wire did and checked the voltage and the current of all the functions of the clock paying close attention to the current when the relay to the heater was tripped.
The voltage to the clock was higher than the 5 volts marked on the circuit board this was probably due to the power circuit not having a regulator and the current went up when the relay was tripped.
Step 4: The Alarm
From my salvaged parts I selected a Piezo buzzer with a built in driver circuit and replaced the heater relay. I tested the clock circuit once more making sure the current did not vary much from the original circuit setup.
As with the heater relay the current doubled.
Step 5: Upping the Buzzer
The buzzer was loud and annoying but I wanted to see if I could make it louder with a larger Piezo buzzer so I built a driver circuit for a Piezo buzzer I salvaged from an out dated smoke detector. We all know how annoying a smoke detector can be if you have ever set one off.
There was no appreciable difference so I decided to go with the buzzer with the built in driver circuit.
Step 6: The Finished Wiring
There were four wires to the clock circuit one power supply wire, one common, one relay that I used for the buzzer, and one for a function I did not need.
I removed the wire for the function I didn’t need.
The relay wire was a ground switch so I connected the Piezo buzzer circuit to the power supply post and the relay wire.
Next I connected the battery terminal to the clock power supply post and the common post.
Once I had all the connections made I tested the all the functions of the clock making sure it went off at the time I set it to go off.
Step 7: The Finish Assembly
Everything working it is time to the face back on the clock and attach the buzzer and battery.
First I glue the lens cover on the LED
Then I screw the clear face on the clock with the labeled control buttons.
And using two sided tape I attach the buzzer and the battery to the back of the clock in a manner that uses the battery as part of the support to hold the clock upright.
Last I test all the functions making sure the clock goes off at the time I set it for.
Step 8: Your New Alarm Clock
There you have it a coffeemaker repurposed as an alarm clock and remember, “DO NOT USE NEAR A GRAVEYARD IT WILL WAKE THE DEAD.”