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AC Adapter for compact FM Transmitter

I have a compact FM transmitter that runs on three AA batteries. I'd like to get an AC adapter for it but am not sure what specs are necessary.

At first I was thinking that a 4.5 v AC adapter at around 300 mA, similar to the one for my discman, would do, but I've noticed that my small Belkin Tunecast II can takes a DC input of 12v at 200mA, which makes me think that the AC adapter should also be rated at 12v.

I think the IC on this transmitter is the cheapest one available that has PLL tuning (Rohm?). My limited understanding of the finer aspects of electronics tells me that I must know the power requirements of the transmitter's IC to determine AC adapter suitability. The only problem here is that the manufacturer has sanded off the chip's identification markings so as, I suppose, not to give away its trade secret.

Thanks for any help you can offer.

ES

Reply to
esantoro
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Three ordinary Alkaline batteries will provide 4.5V DC not AC

If you were to remove the batteries and connect the output of the mains adaptor to the battery terminals then the spec you need would probable be

4.5V DC @300mA . A current rating of 300mA should be ok because it's unlikely the output power is more than 1W.
Reply to
CWatters

Thanks so much for your reply.

I'm quite sure that the transmitter is less than 1 watt. It has a range of about 100-120 ft.

Ok, then , I'll go ahead and try my universal regulated mains adapter. I have one that is something like 1.5v, 3v, and 6v at 300mA, and onother that is something like 1.5v - 12v at 1000mA. I feel more comfortable with the former, but to my understanding the regulated universal adapter rated at 1000mA should also not be a problem.

There is still one thing that concerns and intrigues me: My little Belkin Tunecast II runs on two AAA batteries, yet the DC input is 12v at 200 mA. This has me wondering if I should not also apply the same to the transmitter in question.

Thanks again for your help. I'll be sure to post my results when all has been tested.

ES

CWatters wrote:

I'd

mains

probable be

Reply to
esantoro

but no 4.5V? That's what you need if you plan on connecting to the battery terminals. If the transmitter has a socket on it for a mains adaptor you need to check the specs for what that requires. Without more info we can't help.

Reply to
CWatters

Oops, It also has 4.5v. I'll give it a try.

the transmitter has only the battery compartment, no socket for a mains adapter. I'll rig something like alligator clips to the mains adapter. By chance is there some kind of plug I can put in two of the AA slots that conveniently can connect to the adapter?

Thanks again.

By the way, I was a little disappointed with this transmission quality of this transmitter, but I found out that the problem is that I was running the mini-plug from my computer speaker's headphone jack. On a whim I plugged it into the soundcard instead. Noticeable difference.

This transmitter is manufactured in China and has the name "LineX" stenciled on the front. It doesn't look very cool but rather simple and unsophistocated. It's actually one of the best transmitters I've tried. I just went outside to test the range again (Ray Charles as clean and clear as if it were a commercial broadcast). Plugged into the comp's soundcard I get something that seems like the advertised

150ft range.

You can pick one of these up on Ebay for about $20 plus $6 shipping. If you want a cheap whole house solution, I think this will satisfy. Just make sure you get one with an external wire antenna (I'd like to modify this to increase the range, if possible). I think the first version has a wire antenna coiled inside the case, which gave a range of about 15 ft.

Thanks aga> > Thanks so much for your reply.

adapter.

battery

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Reply to
esantoro

I've seen dummy AA cells in the past but no idea where to get them. They are designed for use in a four cell battery holder whan you only want to use three cells. If you use three of these remember to cut the metal link in one of them or you will short out your mains adaptor.

Reply to
CWatters

mains

I'm confused, my Belkin Tunecast II has a adaptor socket. I just can't seem to find a wall adaptor (AC outlet) any clues? I thought for sure I could buy it on/thru belkin as an accessory.

Reply to
pushup23

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