SDS100/SDS200: SDS100 in the car, hardwire power question

Nudgy

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Hi All, just upgraded to a SDS100 from a BCP325P2. I've had the 325 hardwired (no batteries) into my car (via a usb cigarette lighter adapter) and as has been well for multiple years. I plan to do the same set up with the SDS100, just wanted to ask if other folks here are doing the same thing, and how thats been going for them.

My biggest concern is potential voltage spikes when I start my car. Has anyone here ever fried any hardware due to that? And does anyone have any recommendations on cigarette power adapters that have voltage spike protection built in?

Thanks!
 

nessnet

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Ubbe

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You can buy a $10 12v to 5v converter that you plug in instead of a fuse in the fuse box and select a fuse that goes powerless when the engine starts and also when you leave your car. If you use the scanners mini USB connector you will have the option in the scanners menu to select if you want to charge its battery or not. Any 12v to 5v converter will not produce spikes on its 5v output, but of course a low quality converter can be damaged and stop working due to too big spikes too often.

/Ubbe
 

n1chu

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The BCD325P2 does not write to an SD Card every time when you turn it off manually, because it has no SD Card. The SDS100 does. If you make any changes to your programming with the BCD325P2 it’s remembered immediately and automatically. The SDS100 doesn’t remember anything until it is shut off manually using the on/off switch on the radio, while there is still power connected. When you shut off the SDS series of scanners it first writes to the SD Card before totally shutting down. This could cause a SD Card coruption problem, but only if you intend on using the record function. (There is one other function that could also do the same as the record function but I forget what it is. /Ubbe, a little help here please.)

/Ubbe writes suggesting using a fuse tap on a fuse that looses power when the car shuts off. But while that’s how I would do it also, you’ve got to keep in mind if you use the record function on the SDS100, there’s a good chance you may corrupt the SD Card because it doesn’t get the chance to write to the card before it is divorced from power. And no one wants to corrupt the SD Card. (There have been no reports of corruption with those who use this method to shut down the SDS series provided they are not using the record function.) Since I do not use the record function with my SDS200 I have no issues with the scanner not being able to write to the SD Card when the vehicle is shut off, using the method /Ubbe describes. Since both the SDS100 and SDS200 work the same way, you will not have a problem, provided you don’t use the record function. However, keep in mind if you make any program changes to the SDS100, those changes won’t be remembered when the radio is divorced from power in the this manner. So, after you make a change you wish to keep, turn the scanner off manually, while it’s still being powered, and let it write the changes to the SD Card. Then, turn it back on. Your changes will now be remembered.
 

AK9R

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Get one of those cigarette lighter things with a USB power outlet - make sure it is >2 amp output.
Yes, the higher quality the better.
I have had trouble with cheap cigarette lighter USB power adapters creating a lot of RF noise on VHF. I switched to Anker adapters and the problem disappeared.
 

KK4JUG

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Anker stuff is a little more expensive but it's definitely quality merchandise. That includes chargers, wireless chargers, hubs, cables, etc.
 

Ubbe

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(There is one other function that could also do the same as the record function but I forget what it is. /Ubbe, a little help here please.)
Just the record function, but there are two different ones. You have the manual record that records all conversations to the SD card and you have the replay function that only stores the last couple of minutes and deletes any older recordings. But both will open a file and start writing to it and if the power are lost that open file will not be closed and will create a file corruption, that usually can be fixed by Windows.

The file allocation table keeps track of where on the SD card a file are stored and if that file allocation table are open to be written to, to update it with the recorded file that are being saved, it could trash the whole SD card when the power are lost and needs to be reformatted. There's usually a second backup file allocation table that have the last updated data prior to this last saved file but probably needs a file recovery software to be used to be able to restore the file system. You will have you last config anyhow in Sentinel/Arc/Proscan so just do a quick reformat and reprogram the SD card, if you don't have precious audio recorded that you wish to keep.

/Ubbe
 

tvengr

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Just the record function, but there are two different ones. You have the manual record that records all conversations to the SD card and you have the replay function that only stores the last couple of minutes and deletes any older recordings. But both will open a file and start writing to it and if the power are lost that open file will not be closed and will create a file corruption, that usually can be fixed by Windows.
Where in the menu is the manual record setting? I have playback turned off.
 

RMason

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sfb88

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I will defer to the experts here to answer this. Would it be possible to design a circuit that would include something like a supercapacitor and sense the power loss when the car is turned off and use the supercapacitor to provide a few seconds of power to permit the scanner to complete writing to the SD card?
 

RandyKuff

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I understand your chain of thought...
But... The scanners wright to the SD card when they are physically powered off... Holding up the 12volts to it will accomplish nothing but delaying power loss to it...
That can get pretty complex trying to do that in that period of time buy somehow getting the scanner to power down itself without you doing it...
 

Nudgy

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Perfect! I was able to verify that my car does indeed kill the power to all the accessories while it is cranking over, which alleviates my concerns for them most part. I do not use the record function at all, but I will for sure keep it disabled when the scanner is in my car. Hopefully uniden will have a firmware update, with an option for the scanner to automatically power up upon usb power. Maybe one day :)

Thanks all
Adam
 

Ubbe

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Would it be possible to design a circuit that would include something like a supercapacitor and sense the power loss when the car is turned off and use the supercapacitor to provide a few seconds of power to permit the scanner to complete writing to the SD card?
The on/off switch in the volume controller are only sending a signal to the CPU that then starts to save data to the SD card and then turns off its voltage regulators that has an on/off pin to use.

Yes. A 5 volt capacitor to power the SD card interface and the CPU, that will already have a 3,3volt regulator powering it, would work to let the CPU run for 5 seconds. It would need one additional voltage regulator or electronic switch from that capacitor that can be controlled in parallel to the other regulators that are controlled by the CPU to isolate it from the scanner when it is powered off, or the super capacitor would be damaged if it is drained to 0 volt.

Judging by the BCT15X schematics the CPU power off sense can either come from the on/off switch or from when the 12v power goes too low. So it's probably a similar function in SD scanners that will then sense when the power are lost. If we had a schematic we could probably do that modification without too much trouble, or Uniden could do it in their next scanner model.

/Ubbe
 

KK4JUG

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Perfect! I was able to verify that my car does indeed kill the power to all the accessories while it is cranking over, which alleviates my concerns for them most part. I do not use the record function at all, but I will for sure keep it disabled when the scanner is in my car. Hopefully uniden will have a firmware update, with an option for the scanner to automatically power up upon usb power. Maybe one day :)

Thanks all
Adam
Every car I've owned in the last 40 years or more does that. The starter motor pulls so much from the battery that most of the stuff would be inoperative anyway.
 

Ubbe

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Hopefully uniden will have a firmware update, with an option for the scanner to automatically power up upon usb power. Maybe one day :)
Make that as a request to the wish list that @JoeBearcat manages.
When you power from the USB connector the CPU starts up to handle the battery charge function. That menu function for battery to select to charge or not charge could have another setting to automatically power on at USB power. It's just a simple 2 minute change to the firmware to add a couple of lines of code.

It could also be done as a hardware mod, by using a capacitor and a resistor in series from the USB 5 volt to the power on sense transistor for the on/off button. The capacitor would be big enough to simulate a 2-3 sec key press of that on/off button. But without schematics it would take a lot of detective work to trace out the circuit.

/Ubbe
 
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