Radica to Hip screen, How do i rewire to get 4 AA's?

Neo_Weapon · Post by **Neo_Weapon** » Sun Jan 23, 2005 10:53 pm

I did some searches and i read ladyada's power requirements but i had no clue what she was talking about. How do I rewire the screen/radica so both will run off of four AA's? Also, how do i get rid of that glue that is stuck on to the radica controller wires?

Post by **Sparkfist** » Sun Jan 23, 2005 11:03 pm

Well according to the info Ladyada left us; the screen runs off of as low as 5v so thats not a problem you can wire the screen right to the batteries. The audio amp is something different, she said it requires 8v, and that if you want the video controlls that are on the same board can be removed and the video's defalt settings dont look bad.

So just wire the screens power to the circuit you have to power the Radica, and either use the headphone plug for audio or build a replacement audio amp.

Good luck.

Neo_Weapon · Post by **Neo_Weapon** » Sun Jan 23, 2005 11:34 pm

I see, well i took a look at the lcd control board and i dont see the wires for power. I see the brown and yellow which is used for video and vid gnd, white and pink wires that connect to the lcd screen, and a band of wires that are stuck together that hook up to the control board (this band consists of 6 white wires and a pink wire). Could this be the power source wires? Also, if i add a headphone jack or audio amp, does this increase my voltage requirement? Also, how do i get rid of that glue? Thanks a lot!

A.J. Franzman · Post by **A.J. Franzman** » Mon Jan 24, 2005 12:24 am

Neo_Weapon wrote:I took a look at the lcd control board and i dont see the wires for power. I see the brown and yellow which is used for video and vid gnd, white and pink wires that connect to the lcd screen, and a band of wires that are stuck together that hook up to the control board (this band consists of 6 white wires and a pink wire). Could this be the power source wires? Also, if i add a headphone jack or audio amp, does this increase my voltage requirement? Also, how do i get rid of that glue? Thanks a lot!

First, re "a band of wires that are stuck together" - this is called "ribbon cable". Please learn and remember this term, it's a very common material in electronics.

Second, since that ribbon cable goes over to the lower left area near where the POWER switch is located, there's a very good chace that at least 2 of those wires are for the power.

Third, if you add only a headphone jack (using the existing audio amplifier), it will not increase any power requirement. If you add an audio amp, it could increase the voltage requirement, depending on exactly what you add - but I don't think you asked the right question. Why add an audio amp when the unit already has one? If you want louder sound, you might be able to put in a louder amp that runs on the same voltage - this will increase the requirement for CURRENT but not voltage.

Finally, I can't be sure how to help you with the glue without more info. Is it very hard, or kind of rubbery but really stiff? If it's a hard glue, it's probably epoxy, and there's not much you can do with it. If it's a bit rubbery, it's probably hot melt. In this case, you might just be able to peel it off with your fingernails or some small tools, or you could try melting it with a heat gun (careful not to overheat anything else! a hair dryer is not a heat gun) and swabbing it up with Q-tips or something. This would leave a thin residue behind, but nothing to worry about - you can solder right through the stuff.

Neo_Weapon · Post by **Neo_Weapon** » Mon Jan 24, 2005 12:41 am

A.J. Franzman wrote: Third, if you add only a headphone jack (using the existing audio amplifier), it will not increase any power requirement. If you add an audio amp, it could increase the voltage requirement, depending on exactly what you add - but I don't think you asked the right question. Why add an audio amp when the unit already has one? If you want louder sound, you might be able to put in a louder amp that runs on the same voltage - this will increase the requirement for CURRENT but not voltage.

The current audio amp on the unit uses 8v, so i was thinking about replacing that with one that requires less voltage (maybe 1-4v?) and was wondering if that's possible? Would I harm the lcd if i randomly hook up the power wires to two of the six white wires from the ribbon cable?

A.J. Franzman · Post by **A.J. Franzman** » Mon Jan 24, 2005 12:51 am

A good question might be, does the audio amp in the unit need 8V? If most of the rest of it will run on 4.8 or 5 or so, has anyone tried removing and bypassing the 8 volt regulator?

Also, why hook up power randomly to the ribbon cable? I just pointed out that one end of it is near the on/off switch. There is a very good reason why I did that. Maybe you can have a closer look at things and figure it out before taking a chance of toasting your gear. I can't do it for you...

Neo_Weapon · Post by **Neo_Weapon** » Mon Jan 24, 2005 1:35 am

A.J. Franzman wrote: Second, since that ribbon cable goes over to the lower left area near where the POWER switch is located, there's a very good chace that at least 2 of those wires are for the power.

I thought you weren't sure if those two wires were the ones for power, that's why i asked if i should randomly hook up the wires. Here's a better view:

It seems that these wires are colored differently than ladyada's version.

diggerdanh · Post by **diggerdanh** » Mon Jan 24, 2005 7:24 am

It is never a good idea to "randomly hookup wires". It could very well harm the lcd.

A better way, as A.J. was trying to point out, would be to find the power source (where the current batteries feed into the board) and then attempt to follow the traces to the ribbon cable to determint pos and gnd. A multimeter would be perfect for this task! They're not very expensive, you can get them at any Radio Shack, Sears, hardware store, etc. You're going to need one eventually, might as well get it now.

Post by **Sparkfist** » Mon Jan 24, 2005 9:03 am

A.J. Franzman wrote:A good question might be, does the audio amp in the unit need 8V? If most of the rest of it will run on 4.8 or 5 or so, has anyone tried removing and bypassing the 8 volt regulator?

Yes someone has tried

As for the pin out or color of the wires. They seem to match well with the colors on Ladyada and my Hip Screen. I know its a little confusing to read and translate into something you know how to use. But just look at it by catagory or each board, if you still get confused just tape a label to the wires so you can remember.
Anyways more specificly the wire on the left side of the board that looks red is most likely the orange wire. Just print out the info so you have it on hand.

scherzo · Post by **scherzo** » Mon Jan 24, 2005 10:14 am

What I'd like to know... can the Hip screen be used without the adjustment knob board?

Post by **Sparkfist** » Mon Jan 24, 2005 10:28 am

scherzo wrote:What I'd like to know... can the Hip screen be used without the adjustment knob board?

I know someone is going to call me a hypacrite, but try reading the post before you make your own. I mentioned that Ladyada told use that you can remove the control board and the defalt settings are not bad. So the answer is YES!

This thread is nothing more than an out-spill of the one that Ladyada started. Read what she wrote about it there and than you should understand the screen better.

scherzo · Post by **scherzo** » Mon Jan 24, 2005 11:02 am

Yup, caught me red handed. I'm guilty of not using search. I'd like pepperoni on my tombstone.

A.J. Franzman · Post by **A.J. Franzman** » Mon Jan 24, 2005 1:44 pm

Ladyada's thread doesn't say if anyone tried running the audio from 5V (removing and bypassing the 7808 regulator).

ladyada wrote:TDA2822 is STA 1W headphone/audio amp, requires 6-12VDC

This is all that's there. It isn't clear whether she's guessing or quoting specs here, but a .pdf datasheet I found online says the TDA2822 works from 3 to 15 volts.

If someone wants to try it, just unsolder the 7808 and add a wire across where the 2 outside pins were. As long as your supply is not over 15 volts it should work fine, maybe a little quieter if you're using 5 volts but it should at least work.

cennar · Post by **cennar** » Mon Jan 24, 2005 3:06 pm

you know what i did.. i left every thing alone and pluged in 4AAs to it and it worked just fine. and a nine volt works fine too

cennar · Post by **cennar** » Mon Jan 24, 2005 3:15 pm

Neo_Weapon wrote:
A.J. Franzman wrote: Second, since that ribbon cable goes over to the lower left area near where the POWER switch is located, there's a very good chace that at least 2 of those wires are for the power.
I thought you weren't sure if those two wires were the ones for power, that's why i asked if i should randomly hook up the wires. Here's a better view:

It seems that these wires are colored differently than ladyada's version.

whats that white thing in the back there?