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How to wire a Screaming monkey to a timer? Answered

I have a few cheap countdown timers I  bought off of ebay. I want to wire one to a Screaming Monkey so I hear the Monkey scream instead of the normal beeping.


So, uh... what do the Screaming Monkey, and Countdown Timer, look like electrically?

How many batteries does each device use? That is to say, what does each device's power supply look like? 

Concerning the switch that activates the Screaming Monkey:  to which side of its supply is it connected?  Guessing that it pulls an input to the low side of its supply, or it might be the high side?

I might ask the same question about the buttons of the timer, in the event that it is desired to make the alarm turn itself off, in addition to activating the Screaming Monkey.

I think the usual trick for this sort of think is to take the signal that used to go to the alarm, and rectify it into DC  (e.g. using just a diode and a capacitor).  Then this small DC voltage is used to turn on a transistor, and that closes your switch.

Or at least I have done it that way before.

Ok I guess I should have taken one apart before I asked the question. The timer uses a little watch battery but I've changed a few to take AA batteries. The monkeys are called super fly screaming monkeys. You normally fling them threw the air and they scream. I am a adult baby sitter and my job requires me to check on my um misbehaving adults every 30 minutes. I like to add a little humor to my job and I thought a stuffed monkey with a timer attached to it going off at every check would be funny.
I will take a timer apart and post images when my new supply of monkeys come.

Ok new supply of monkeys came in today. The switch that activates it is a little coil spring that touches the outer metal ring.


Well, lets take a look at the Screaming Monkey board first. I rearranged a couple of those pictures, and I drew some numbers on them.

I labeled the power wires as nodes 1 and 2. I still don't know what voltage, or what polarity those are, but I am guessing that 1 is the low side of the battery, and 2 is the high side.  Also guessing that the high side is higher by 1.5 V, or maybe 3 V DC. Also guessing that when the bump-sensor gets bumped, the wobbly contact in the center touches the outside, ring shaped, contact.  I labeled the wobbly contact as node 3. I am guessing that the ring shaped contact is connected to 1, and thus the low side of the battery. Guessing that when 3 and 1 are touched together, this activates the screaming. Also it looks like that little ceramic capacitor might be wired in parallel with the bump-switch.

Are any of these guesses correct?


looks like 1 for the power wire would be - and 2 would be +. It has 3 watch batteries that power the monkey so that should be 4.5 volts. Maybe this can't be done. The timer runs off of a watch battery, but I add a AA battery holder and change them to that.
The speaker on the timer is a coil of wire and a metal plate. On the back of it had +- labeled to it so I had hoped I'd get a voltage reading off of it and be able to run the monkey. For some reason I can't get a reading off of it but the timer works.

I drew a diagram to sort of show you how the Screaming Monkey board, and the timer, might look together sharing the same stack of battery cells.  They share a common "ground".  The timer is powered by one battery, and the Monkey Module is powered by three batteries.

Link to big version here:

Also included in this diagram are some transistors and other stuff.

Q1 is the NPN transistor that activates the screaming monkey.  When Q1 turns on, its collector gets pulled low (from 4.5V to 0). 

The base of Q1 is driven by the output of a voltage doubler, which is driven by the alarm signal from the timer.

Q2 is the PNP transistor that "presses" the stop-button on the timer. When Q2 turns on its collector gets pulled high (from 0 to 1.5).

At least that's the theory.  As drawn this circuit probably won't work exactly the way it is intended to, and at this stage in the game it is only intended as a broad outline of how these two electronic thingies (the timer and the Screaming Monkey module) might get married together.


Thanks for taking the time but I think this is beyond me. Maybe one day I'll find someone who would do this for me for a few dollars.

I have a screaming monkey that I often hurl at misbehaving employees, (not really the hurling part).

They work using some kind of impact sensor switch to turn on the sound circuit.  I is a momentary on type switch.

You need to find out what the output voltage of the timer is then build a one shot switch that you can then hook inplace of the impact switch on the monkey.  The one shot should not reset until you manually reset it.

Google "one shot switch" and look at what you come up with.

You might be able to do it with just a relay that works on the voltage from the timer using it in place of the monkey.

I want to be able to reset it by pressing the reset button on the timer.

This must be some kind of animatronic Screaming Monkey, and not a literal screaming monkey. Because if you like to hear the sound of monkey screams, well I think that's a little bit weird, not to mention sick and wrong.

First, go down to your local monkey supply depot...........


6 years ago

screaming monkeys often bite so anything that you wire to one might cost you more than its worth. They have also been known to throw poo.

Poo coated wires are difficult to work with also.

Probably poo coated timers will not keep time very well anymore.

Finally, any wires that you do manage to get them hooked to will get yanked out unless you tape their little hands and feet together in which case your gonna get into trouble with PETA. They might stage a nude protest in front of your house. Hey, can you shoot a You tube video of that for us?