Wiring up a radio using 12v

[Guest GA/Triker]

Is it a very difficult thing to wire up your transceiver to run off the Trike's battery. I am not an auto electircian nor do I have much of an idea when it comes to these sorts of things. If anybody can suggest where I can go to get some help that would be great.

 

Thanks

 

 

[Dieselten]

I prefer to wire up trike radios to the output of the voltage regulator rather than directly to the battery. If there are large voltage spikes in the charging circuit (from alternator to battery, usually via a half-wave rectifier diode) then your radio also gets hit by the spikes...and may be damaged.

 

Via the regulator usually isolates the radio from the "raw" DC and AC ripples present in the charging circuit, even after the diode rectifier. A decent regulator (the Key West seem pretty good) does a good job of protecting your radio.

 

You could add a passive DC filter to the power to your radio input power lead if you still want to connect directly to the battery. Similar units are used in some mobile phone in-car kits. They are usually a choke and capacitor arrangement...the choke (inductor) is usually in series to prevent large transient spikes getting through and the capacitor is usually in parallel across positive and negative rails, to smooth the incoming DC.

 

The neat trick is working out the values of the choke and capacitor to give effective suppression of the transients. The reactances of each component (choke and capacitor) are dependent on the frequency of the incoming ripples. Capacitive and inductive reactances tend to cancel each other out (a very useful thing when you wish to make a resonant circuit for radio transmitter) and you'd need to have a good idea of what the values of the ripple and transient spikes are in your supply to the battery to design a passive filter that was effective.

 

What you want is an impedance (the vectorially-summed reactances of both the the choke and capacitor) which blocks the AC ripple and spikes, whilst permitting the DC through. As both frequency and amplitude of the incoming AC ripple on the DC battery-charging line varies constantly, this is no easy feat.

 

Wiring to the output of the voltage reggie just avoids a lot of hassles!

 

 

[myshed2]

Shees, if Andy wasn't confused before I bet he is now Dieselten, but good answer all the same.

 

 

[wanabigaplane]

connecting radios.

 

If you want to add a filter you can get a ready made filter in a shiny can at most cheap automotive stores. The instructions with it will show you how to wire it in.

 

If you have an ignition system connect the radio after the switch for your ancillaries. Most wiring systems allow you to switch the radio and instruments off while you are starting the engine.

 

If you do not have an ignition system, connect the radio as close as possible to the battery. In case of a wiring failure or poor connection, the battery will protect your radio from any high voltage excursions. If the regulator fails, the radio will survive until the electrolyte boils off. Higher than normal battery voltages, or electrolyte boiling off more quickly than usual is the first sign of regulator failure. For this reason, a battery electrolyte level inspection should always be a part of you pre-flight inspection.

 

Jack. :):)