Birthday cards nowadays can be really cool, With moving parts, blow-outable candles, and especially speakers. But these devices often run out of battery, break, or get thrown away.
What if they were reused?
This instructable will help you make a "Birthday card reader" with louder speakers, replaceable battery and (depending on the card's micro-controller) sound effects!
Step 1: Disclaimer
This project involves opening up and dissecting birthday cards, and unless properly done, the card could be easily destroyed. It also involves possibly using slightly more volts than the cards chip is designed for. It also possibly involves overloading a resistor on the circuit which could blow out the chip. This is not to say any of these things will happen, they haven't happened to me yet.
Step 2: Parts
the parts are really up to you and your aesthetic tastes, but essentially you need...
1. A battery pack - should hold 2-3 1.5v batteries, giving you a total of four and a half volts(above necessary amount of power, but louder) or 3 volts (the voltage these things were designed for.)
2. A speaker - the speaker pictured here is inside of a remote control car tire, but you can see that it is a much larger, more powerful speaker than standard Birthday card issue, but any speaker will do.
3. The chip - This chip (taken from the birthday card should have abbreviations of which solder point does what (for example: spk stands for speaker). If your chip doesn't have these marks, that's OK, just look at what solder joints are connected to the speaker on the card and use those later. NOTE: THIS PROJECT IS MEANT FOR SOUND CIRCUITS ONLY. IF YOUR BOARD CONTROLS A DANCING FROG AS WELL AS SOUND, THIS PROJECT ISN'T RIGHT FOR IT.
4. Alligator clips - Get two of them, split them in half, and use two halves for power and two for sound.
5. The casing - up to you obviously. I am using a recycled toy car tire.
Step 3: Step 1: Geting the Chip
Here are two birthday cards intact and one taken apart. once again, if your card does anything but play sound, this probably isn't the project for you.
I'm going to concentrate my efforts on the openable card because it's more generic.
I lobotomized mine, but if you want to preserve you birthday card, its possible to undo the powerful sticky stuff around the edge. Try using a heat gun or hair dryer.
In the second picture the pull tab is clearly visible. when the card is opened that bit of metal is touched to the bit underneath, completing the circuit.
Step 4: Step 2: Looking at Your Chip(s)
After 5 minutes i got it out, and my card isn't completely destroyed. You could be a bit more careful... :)
I have a pretty complicated chip: it is an unexpectedly high 6v, although it should work with less.
It also has the ability to record and store an additional sound file to be played when another button is pressed.
For the simplicity of the project I am going to use my very simple sound chip I previously dissected, though this chip could be used.
Step 5: Step 3: Setting Up the Speaker
Snap and strip the wires of your Alligator clip and then solder or attach with tape (its much worse than soldering) the wires on. You now have your speaker prepared.
Step 6: Step 4: Setting Up Batteries
Cut one alligator clip in half. Each of these halves should then be soldered to the battery pack.
It may be helpful if you distinct the two wires, because one will be positive and one will be negative, And your alligator clips might need to be lengthened with wire, as I did.
Again, it is probably best if your battery pack uses 3 or 4.5v.
Step 7: Step 5: Putting It All Together
Assembly is up to you, I used a couple of parts I had lying around.
Now that the device is built, we need to connect chip(s)
Step 8: Step 6: Connecting the Chip
Using scissors or cutters, take off the top of the watch battery holder. take out the battery.
Connect the negative alligator clip to the little metal square under the tab, then connect the positive to the big circle of metal where the battery used to rest. The two wires should be connected to where it says spk on your chip.
Step 9: Step 7: Use
If you added a switch push it. Your birthday card should play. When you touch any resistor, your finger will override it. If you touch the resistor between the power, it will make the sound fast, high and squeaky.
This project was designed to be used with multiple chips. If you only have a single chip, you could solder it on instead of connecting it with the alligator clips.