Surge Protection...

[ES13Raven]

I want to be able to turn the car on and have the RX65 turn on with the ignition, which is how I have been running it. When I turn off the car, the power to the detector turns off as well. I ran the direct wire kit to the radio fuse tap.

I spoke with Chad from Bel today about this, and he says that is the best way to run it and that the radio power is the best to tap from because it is filtered for noise etc.

I asked him if having the RX65 start up and turn off with the car could cause the "self cal" or "service required" messages and he said no.

He also said that under-voltages would only be a problem during start-up and if they were frequent - not when the car loses power and shows "low voltage" for a brief second.

[amoney]

If the detector is plugged in but not powered on, while starting the car I have noticed a popping noise that comes from the RX65 so I am assuming that power is flowing through it.

I was meaning to comment on this earlier, as I can also confirm this "pop" noise from the RD speaker, only when I do a hard startup (not intensionally), that is to quickly turn the key from off to cranking the engine up, in one swift move. If I do a "gentle" start, there is no sound from the RD, again the unit is off during these events. So obviously power surge of some kind is flowing into the unit while still attached to the cars electrical system, mine is attached to the cig lighter which only powers on upon ACC power is engaged.

When cranking the engine, the ACC power shuts off for that brief moment, the radio normally does shut off during this bit as well, however there are occasion that the radio stays on with out interuption.

Bel985

[burner42]

Ok after reading all this... if I simply power off my RX65, then unplug it from the actual detector (phone style plug, I leave the cord plugged into the cig. lighter)) before starting and stopping my car I should be ok, right? I dont like unplugging the lighter cord everytime I stop and start my car, I dont want to wallow out the hole or make the plug become loose.
Myles

[ES13Raven]

Ok after reading all this... if I simply power off my RX65, then unplug it from the actual detector (phone style plug, I leave the cord plugged into the cig. lighter)) before starting and stopping my car I should be ok, right? I dont like unplugging the lighter cord everytime I stop and start my car, I dont want to wallow out the hole or make the plug become loose.
Myles

There is still speculation if this is part of the cause of the "self cal" and "service required" issues, but that is the safest way to handle power to your RX65. You could do this everyday and still get those errors. These messages may be due to excessive heat too. No one is sure yet.

[holein1]

This is what I use, never had a problem!

[SmaartAasSaabr]

As long as it is unplugged, it is unplugged :roll:

How about just powering off the unit anyway?

[amoney]

As long as it is unplugged, it is unplugged :roll:

How about just powering off the unit anyway?

Some users experience (RD/car combination) like myself, that posted earlier, have noticed a electrical "pop" or "click" sound from the RD speaker even though the RD is turned off, for me this only happens if I start the car quickly with out pause, if I simply rotate the key and power acc, then 1 second later start the ignition, the RD does not emit a sound. But every time I quickly start the car, the RD speaker makes that noise, its a small noise, but it is annoying not knowing what the hell is happening. Again it probably is a certain RD/car combination. Idealy I would aire strieght to the car battery with a fuse inbetween.

[SmaartAasSaabr]

If I turn it off, then reconnect it, does it remain off or power on? For me always remove it from the car so no big deal.

[HighVoltage]

A couple of things to throw into the conversation:

First, a battery is a VERY consistant power source unlike say a generator. Batteries provide an extremely steady voltage source and the voltage dropoff is generally quite predictable. However if there is a voltage loss at the battery (say you left the lights on for extended period), the voltage regulator from the alternator will begin increasing the voltage output so that current will flow from the alternator to the battery and begin recharging. However when you turn the key an event known as inrush current occurs. Every electrical devices has a nominal current draw, but it also has a maximum. The maximum usually occurs as a spike during the first few uS (microseconds) of applying power. Usually large capacitors are placed in parrallel on the system to help handle events like this, especially with extreme audio systems.

EDIT: Frankly, fuses generally are in place to prevent the accessory (RD) from damaging the voltage system and not vice-versa. In the event the system is supplying an excessive voltage (it cannot supply an excessive current) the fuse can act as a circuit protector for the accessory. However, the reaction times of most fuses are usually in terms of ms (milliseconds), so they do not generally protect from any kind of "spiking", but rather are a protection in the event of a fairly steady state condition.

The max/min input voltages of the RX is strictly determined by the power circuit. If it is a simple linear regulator then it is probably quite wide (~5v to 40v). If it is a switching supply, it is generally much narrower as the wider the input range on these kind of supplies, the more $$ the cost (somewhat exponetially). In any case, an engineer worth his/her salt would/should simply install some kind of voltage clamping to prevent an constant over voltage from destroying the circuit. Granted this doesnt cover fast voltage transients (FVTs), which may be the source of the issue.

Second, when your crank the engine over, you are consuming the largest amount of power from the battery to supply power to starter. Its possible some vehicle starters are producing a significant back EMF that results in a FVT spike onto the system that the vehicles system isnt prepared/designed to handle appropiately.

Third, even though the switch of the RD is in the off position, the power input circuit could still be connected, but no load is being applied. Hard to tell without a schematic. Even then, if the RD isnt switched on it is still possible for FVT to "creep" across the board and damaged other portions of the circuit.

Take all of it with a grain of salt though. I cant imagine a manufacture of $$ equipment not covering themselves on this sort of problem. In fact if the RX65 has been CE tested it likely isnt the source of the problem, as FVT testing (both radiated and coupled) is covered. Usually any electronics sold into Europe are required to go through CE testing. My experience with field failures on circuits tends to have alot more to do with quality control issues of components and assembly then the design itself. Although there is something to be said of designing the product to predict and handle these sort of things as well.

Enough of my rambling. Hope I didnt bore you all to death.

[ES13Raven]

No.... That was very informative :wink: