I'm thinking of a few hacks, including a volume control because the thing is loud, headphone output for playing in public, and maybe a DC input jack to minimize my use of batteries.
Anyone know any other hacks I could do? Is there any homebrew for this system? It uses interchangeable cartridges, but all I have is a blank dust protector that doesn't even have any pins.
Here is what is sais on the back:
Who Wants to be a Millionaire: (C) Valleycrest
(R), TM, & (C) 2000 Tiger Electronics Ltd
All Rights Reserved.
Rating: 4.5v DC 0.675W
Battery: 3 X "AA" or "LR6"
Made in China
Inside the battery cover, there is a green sticker that sais:
C290A
2610A
I opened it up, here are some pictures:
As you can see, the speaker is 32 Ohms and 0.25 Watts. I will probably just add in a variable resistor or potentiometer. I found one in my old radio:
This is what the pins went in the radio circuit (Numbered from left to right):
2: Ground, 3: Input, 4: Output
1 and 5 was used as a power switch... I also found another potentiometer exactly like it that used to be in another FM radio. I ripped it out last year.
As for the DC input, I have a portable radio I can rip a jack out of. I'll drill a hole in the top of the unit, wide enough for the jack to stick out, then glue it with epoxy if I can find any. If I can't find epoxy, I'll use hot glue as a temporary solution. I have a universal AC adapter I can use. I'll wire the jack and the battery leads to a DPDT swith to switch between the two, And I found one in my old radio, in one of the pictures below. You can also see that the DC connector sticks out quite a bit, which is great. That means I don't have to have the input jack sticking out.
For the headphone jack, I think I can just drill another hole somewhere on the top of the unit. I'll wire it to my volume control and wire in a switch for the speakers. this way, I can use the speakers and headphones at the same time if I so choose, or just use the headphones. Until I find the charger for the drill, I'm just going to experiment with it open.
Sweet, I found an audio amplifier IC inside my radio! I might be able to use it. The datasheet I found on the internet includes some example circuits.
Heres the pinout:
1-Output(1) 5-Input(1)
2-Voltage 6-Input(1)
3-Output(2) 7-Input(2)
4-Ground 8-Input(2)
Max voltage: 15v
Min voltage: 1.8V
Peak output current: 1A
Total Power Dissipation: 1W
:::EDIT:::
I implemented the audio modifications, and they worked!! The volume control knob is a little too coarse, so I will need to change the capacitor to one with less resistance. The headphone port is fully functional with mono sound
and the speaker switch works like a charm.I also need to drill holes in the case. I decided to bunch them all up at the bottom, that is the only place they will fit, unless I find some longer wire. I might use caulk to glue the parts in. I have some of that.
I still haven't done the DC input modification, but I'm getting to that.
Look at these pictures from right to left, bottom to top. Too many links to organize!
