Very cool FM transmitter and easy wiring question

wompser · 04-23-2004, 05:08 PM

Hello,

Just thought I'd point out the FM Transmitter I just purchased. I've tried the Belkin (apple Ipod) one, and the C Crane and Co. transmitter, but this one is way better (and naturally more expensive) According to the owner's manual, range is 2 miles with the right antenna! (look out for the FCC though...)

The sound is very good, unlike the cheaper ones. a picture is attached.
www.technolab-inc.com if you want to get one for yourself.

I do have a question for you guys though... The input voltage is +9V DC, what is the best way to convert my +12 DC into +9V DC? My other +12V stuff is running off the Opus PSU, but I think for this I don't need to go through the Opus, I just need to convert battery voltage into +9V DC. Or maybe you know differently?

I have a DVD player, Hard Drive, Eden Motherboard, and Datalux monitor all running off the 90 Watt PSU, so I think I might be getting close to the limit of what I can run off the PSU. The power adapter that came with the FM Transmitter says 500 miliamps.

Please let me know what you think the best way would be to drop the voltage from 12 to 9 Thanks!

god_of_cpu · 04-23-2004, 05:27 PM

You can just get a dc voltage coverter from radio shack or

on here for how to build a voltage converter circuit yourself.

480TURBO · 04-23-2004, 05:34 PM

hi all,my first post on my quest to spread the word of the 480 overseas!!

a simple & cheap but fairly inefficient way is to use an LM117 adjustable voltage regulator. just a couple of external components used to set output voltage and it can source up to 1.5A (might need heatsink)

can you solder??
check out the typical application circuit in the data sheet:

http://www.national.com/ds/LM/LM117.pdf

toadster123 · 04-23-2004, 05:46 PM

wow, i lil expensive... but maybe if u really dont wanna run cables....
but, from what i hear, cables will provide better quality..... as long as there is no additional 'line noise' or whatever its called...

wompser · 04-23-2004, 05:56 PM

480TURBO, you must have meant the first application of the pdf (screen capture below)

I think that could work, guess I'll have to pull out the old soldering iron this weekend. I wonder if my local friendly Fry's electronics carries the necessary part. I'd love to get this dang thing finished this weekend! This is the very last thing I need to do to complete it.

God_of_CPU, maybe i'll need to stop into radio shack and see if they have anything, but I just hate shopping there! I didin't think you could buy these pre-built.

wompser · 04-23-2004, 06:14 PM

Here are a few pictures for your viewing pleasure of what this sucker looks like. Naturally the screen folds up into the ceiling to get out of the way...

Kaspin · 04-23-2004, 06:16 PM

Quote: Originally Posted by wompser

God_of_CPU, maybe i'll need to stop into radio shack and see if they have anything, but I just hate shopping there! I didin't think you could buy these pre-built.

Look for one of these:
http://www.radioshack.com/product.as...Fid=273%2D1818

wompser · 04-23-2004, 06:29 PM

Quote: Originally Posted by Kaspin

Look for one of these:
http://www.radioshack.com/product.as...Fid=273%2D1818

Yeah, I guess that is what I need. But $30???? that is highway robbery! I'm sure the components in there don't cost more than $5. Anyone have one that they can make a wiring diagram and component list from?

Chairboy · 04-23-2004, 07:35 PM

Just use a 7509 regulator from radshack. Costs maybe $2 max, no additional parts needed.

shchua · 04-23-2004, 08:59 PM

Quote: Originally Posted by Chairboy

Just use a 7509 regulator from radshack. Costs maybe $2 max, no additional parts needed.

I agree, but I think you meant the 7809 (1A 3 terminal linear regulator). Its recommended to have a 0.1 uF capacitor on the output for stability although you can get away without it most of the time.

freestyler · 04-23-2004, 09:05 PM

Quote: Originally Posted by wompser

Here are a few pictures for your viewing pleasure of what this sucker looks like. Naturally the screen folds up into the ceiling to get out of the way...

yea and i thought my jeep was pretty cool

that's a tad bit extreme for my liking though!

wompser · 04-23-2004, 09:46 PM

Quote: Originally Posted by shchua

I agree, but I think you meant the 7809 (1A 3 terminal linear regulator). Its recommended to have a 0.1 uF capacitor on the output for stability although you can get away without it most of the time.

Uh, it has been a while since I built any circuits like this, would you mind putting together a little wiring diagram for me? I'm not exactly sure what you are recommending. Thanks in advance!!!

Chairboy · 04-23-2004, 11:27 PM

Super easy. This is for the 7812, but the instructions are exactly the same.

wompser · 04-24-2004, 12:21 AM

Thanks Chairboy, I'll go to the store tomorrow and build this sucker. I think this is way better than buying something from Radio Shack. This should be the final component I need to finish up this thing, thanks for your help!

rando · 04-24-2004, 04:20 AM

Pin3 is ground, not -12vdc nor -in.