Hi,
I hope someone can help me out.

Short story:
Over Christmas my car was sort of broken into. The problem is the remote is so powerful it gets pressed in my pocket and the signal travels probably upto 100 meters. My car is nearly always unlocked when i return to it or the boot is popped and I have to pull over and slam it closed.

I need to find a way to reduce the signal strength other than stop putting the key in my pocket.

I scratched the aerial line on the pcb inside the remote key but now its too low, working once in maybe 50 presses sitting inside the car.

So the question is:
Can I solder a resistor or other component in to keep the circuit but reduce the aerial strength?

I'd be really grateful for any advice with this and wish you all a really good day.

Many thanks,

Simon.

 

Perhaps you can put it into a metal container when you put it in your pocket. Actually, if you can find a sleeve for it maybe you can keep the button from accidentally pushing the button. This is a pet peeve of mine too. leave the antenna alone, one day when you can’t find you car in a giant parking lot it will be useful to have some range. They run at 433 MHz and it’s hard to design antennas that small.

 

Something like this: https://www.amazon.co.uk/RFID-Block...t=&hvlocphy=9046728&hvtargid=pla-893881097477

 

Soldering a resistor across the gap can indeed reduce the signal, and also add a resistor from the "downstream" side to the common. Probably 10K for the series resistor and 1k for the one to the common.
I had a similar problem with the doors on my cars, but as the batteries in the remote age the range does drop.
The real problem is that the buttons on the remote do not take nearly enough force to operate. So it gets down to STUPID DESIGN by the original designer.

 

Thanks for the ideas.

I think there might be enough space on the key to add a micro momentary switch (on order now). I'll attempt to add this to isolate the key's battery. Hopefully (if it works) it will mean I need to hold the new switch on then pressing either lock or unlock.

on the other key I'm going to attempt soldering in a 0.15mm nichrome wire as short as possible and make the 1.5 inches of pcb copper aerial redundant.

I'd welcome any comments or help.

thanks.

 

Soldering a resistor across the gap can indeed reduce the signal, and also add a resistor from the "downstream" side to the common. Probably 10K for the series resistor and 1k for the one to the common.
I had a similar problem with the doors on my cars, but as the batteries in the remote age the range does drop.
The real problem is that the buttons on the remote do not take nearly enough force to operate. So it gets down to STUPID DESIGN by the original designer.

Thanks MisterBill2

Can you expand on "from the "downstream" side to the common" please.

I agree about poor design. I've replaced the switched with uprated ones and replaced the plastic casings.
The buttons still press way to easily and not much else I can do from that angle.

 

I think most car owners would be happy to have longer range on the remote.
Perhaps a solution is to find a mechanical means of making it more difficult to inadvertently press the unlock button.

 

Glue a plastic ring around the unlock button...

 

I'd welcome any comments or help.

I wouldn't modify the remote. Just put it in a case that prevents the buttons from being activated accidentally. A stiff plastic sleeve would do.

 

Thanks MisterBill2

Can you expand on "from the "downstream" side to the common" please.

I agree about poor design. I've replaced the switched with uprated ones and replaced the plastic casings.
The buttons still press way to easily and not much else I can do from that angle.

OK, sorry about causing confusion. "upstream" means toward the signal, or power, source, while "downstream" is the direction of signal or power flow. So the connector for the external antenna of your keyless system would be all the way upstream, the gap with the resistor soldered across would be downstream from the antenna connector, and then the resistor from the circuit board would be on the other side of that series resistor. The two resistors would be known as a voltage divider in other descriptions.