Home-made Coyote Decoy

Its winter, know what winter means? Well yes, ice fishing, but today … it’s varmint hunting!  Here is a cheap time delay coyote decoy MacGuyver’d out of some electronic pieces and some things from around the house.

Difficulty : EASY
Time: 30-40minutes

Parts List

1 – 0.01uF ceramic cap
1 – 100uF electrolytic cap
1 – LM555 Timer
1 – 9V battery with connector
1 – DIP Switch
1 – P-Channel MOSFET
1 – 100kΩ resistor
1 – 27kΩ resistor
1 – 100Ω resistor
1 – Power Diode
1 – small DC motor
½ – Fishing Pole
1 – Coonskin Cap (or something furry)
1 – small copper disk for counterweight (use your imagination)
Assorted Cable Ties
Electrical Tape

If you have to ask what you need this for, don’t worry you won’t ever need one.  However the timer circuit can be used in many other applications.

The main parts we have is a motor with a counter weight on it to shake the decoy, the top half of a fishing pole, which gives us something to put the decoy on and gives a nice whipping action, the timing circuit.  Finally something fuzzy and fluffy to catch the varmint’s attention, in this case, a coon skin cap from Disney World.

The timer circuit’s core is an LM555 timer chip.  The LM555 does alot more then just keep time, but in this case its just being used as an astable multivibrator.  The circuit below will put the 555 in such a configuration.

Resistors RA and RB and capacitor C2 are what control the duty cycle and frequency of the circuit.  With the values selected here a period of a little under 11 seconds with about 2 seconds on and just under 9 off.  If you want to have these times be different you can change the RA and RB values, but make sure that the RA value is at least double that of RB or the circuit will not oscillate, which is bad.  Also you can replace RA with a potentiometer giving an adjustable off time.  A more set of the timer equations and instructions are in the LM555 data sheet but the stuff below should be enough for most purposes. It may be a good idea to put the circuit on a breadboard before putting it on a PCB or Project Board so the duty cycle can be honed in to what is satisfactory for the particular application.  One simple way to hone in the desired duty cycle on the bread board is to replace the motor with an LED and appropriate driver resistor, then you don’t have a motor jumping all over the workbench.  Then its time to throw everything on to a PCB or project board.

Once the timing circuit is squared away its time to attach the motor to the half top of the fishing pole.  You can find a small motor around the house in many things.  This particular one was salvaged out of an old Xbox 1 controller.  A single cable tie through the top eye of the pole wrapping around motor works really well.  Guide the wire down the line guides and cable tie to the rod shaft.  As you can see the “small copper disk” has been soldered to some solid core wire wrapped around a few times which is in turn soldered to the motor to complete the counterweight.

Now to attach the rest of the stuff.  Electrical tape can offer a little water resistance if one of those plastic project boxes isn’t available, which is what was done here.

The furry thing can now be attached to the rod.  Don’t forget to leave room for access to the switch.  Also try to leave the battery a bit exposed so that it can be replaced.

Here’s a quick vid of what it looks like when its done.  One thing to note is the off time of the setup in the video since at the time the video was recorded it was setup for a 4 second off time.