Transmitter Diode protection

No need to bypass the diode. Simply add another chargejack and solder the wire directly in parallel with the existing wire on the battery pack

yvan "Barry" a écrit dans le message de news:tRC9b.41858$ snipped-for-privacy@news04.bloor.is.net.cable.rogers.com...

no. charging is constant current, not voltage

Replace the diode with 1amp fuse.

By splicing in a charging jack right at the battery before it connects to the TX circuit, you get to cycle and charge your battery without removing it (I usually find room to install the jack somewhere on the battery cover) but, better yet, you also keep the built-in protection. You win all the way around.

MJC

"If, in the above cases, the diode is removed, will this have any effect on charging as the voltage reaching the battery is now 0.7v higher than it was before?"

Yes and No. Yes, the charge voltage will be .7V higher. But, No, it won't be a problem, because it will only increase the charge current about 5 or 6 ma.

I like the polyswitch idea, because it solves the problem and it easly reversed.

Doug

How does bypassing the diode with a 2nd charging jack keep the built-in protection ?

The diode protect against fire if the charger/charger leads short-circuits.

Replace it with a 1amp fuse.

Thanks for the comments guys, I tinl inititially the I amp fuse wins out, til I can find a supplier for poly switches.

Barry

The diode is primarily to protect the circuitry of the board in the TX, not to "prevent fire". Even with the diode in place, you would still get fire if the battery leads were shorted. I was talking about circuit protection. The charging jack I describe goes BEFORE the battery leads even go into the TX case. The whole purpose of the additional jack is so that you don't have to pull the battery out every time you want to cycle it but still keep the manufactures intended circuitry protection. A diode prevents ANY reverse voltage from getting to the circuit while a fuse does not and you could easily suffer damage to the board by the time the fuse blew.

MJC

wrote in message news: snipped-for-privacy@news.broadpark.no...

How? The diode is in betveen the chargerjack and the on/off switch. the TX circuit is not connected when charging and the diode is not connected when the transmitter is on.

Even with the diode in place, you would still get

I was talking abaut shorts in the charger and its leads. try shorting the chargerleads and watch something I would call a fire.. :-)

So does replacing the diode with a fuse.

Again, the diode is only connected when charging and then the TX board is not connected. when TX is on the diode is not in use.

Just about all of those small components contain a small amount of "smoke and fire" in them to work, once you let it out, the component will not work.;-)

So here's my question and $.02 worth....

How many of you have had radios that did not have this diode protection? And of those radios, how many did you fry, either physcially on fire, or damage the electronics? My guess is none. At least that is how many I've toasted. It's all about paying attention to what you're doing and hooking things up correctly when you want to cycle or charge your battery. It's a barrel connector with two leads... 50/50 chance that is pretty foolproof unless you're color blind.

One option that was listed, bypass the diode with a piece of wire. You want the diode back in the circuit, remove the wire.

And the one time you don't, you FRYIT!!! For the sake of a little inconvenience of taking the battery out to cycle it, is it worh the chance?

I have never been injured in an auto accident, but I still buckle up every time I ride. Dr.1 Driver "There's a Hun in the sun!"

Rascal,

Even though it has not happened to you doesn't mean it won't. What you may not know is that the JR charger for the xmitter is the reverse polarity of the Futaba. If you should happen to own both systems, you stand a good chance of plugging a JR charger into your Futaba some time.

Additionally, with the open structure of the charge recepticle a small screw or some such debri may short the plug while you are in transit to the field, etc.

These are the times you will be thinkful for the diode. It is this time that you will let the smoke out of the wires from the charge plug to the battery which goes via the switch.

The poly switch is the best idea to replace the diode.

Dan

P.S. Yes I damaged >So here's my question and $.02 worth....

Dan Thompson (AMA 32873, EAA 60974, WB4GUK, GROL) remove POST in address for email

Did you ever own a JR and Futaba at the same time? The plug pins are reversed polarity in these. Unless you were clairvoyant or happend to know someone ehi was, you could have easily fried one or the other since common wisdom says that the center is the positive lead. I am sure that there were enough problems with this to force Futaba and others to install the cheapest protection available.

I haven't been hit by lightning but I still won't play golf in a thunderstorm!

Also, some chargers have a JR / STD switch on them, accidently knocking that could be embarrassing!

I have put a dab of CA on the switch to lock it in place as well

Barry

I have a HiTech and a JR - no sweat tho as I have bigish labels on the plugs to make sure I never put the wrong plug in the xmitter -

David - who wouldn't like to wreck his xmitter by continually removing and replacing the battery to do a recharge, and labels leads to make sure things are safe.

Paul Mc>

Do you REALLY not pay attention to which charger you're using? I doubt it!

You're in the basement and the wife calls dinner or the kids need attention. You will accidently plug the wrong one eventually. Murphy's law I think!!!!!! Also the bad connection only needs to be connected for about 20 milliseconds to let all the smoke out.

Dan Thompson (AMA 32873, EAA 60974, WB4GUK, GROL) remove POST in address for email

Also, these small plugs have been known to short internally....

No reason to take chances.