[flickr 198384190 ]
At HOPE I got to look at a cell-phone jammer owned by a friend. This one is interesting because 1) its extremely well designed 2) it’s very small and 3) it actually has a PLL instead of just being open-loop controlled. The entire package fits into a pack of cigarettes.
(For more disassembly photos & comments…)
[flickr 198384118 ]
The design is made of 3 PCBs bolted together.
[flickr 198384044 ]
The silkscreened cover is also the microstripline antenna for the two VCOs
[flickr 198383962 ]
The battery is a large LiIon, there’s a protection circuit that looks like it was removed from something else and soldered on. And a somewhat questionable LM317 charger. I’d only trust a 317 for a lead acid, but I guess if you’ve got a protection circuit the worst is just that you’ll reduce the battery life
[flickr 198383843 ]
I didn’t get too much time with it so I just took photos of the disassembly. Looks like there’s some boost converters, 2 PLLs (16-TSSOP parts), a micro to control them, and the VCOs. A very nice design! And I like the idea fitting it into a cigarette pack.
Have an amazing project to share? Join the SHOW-AND-TELL every Wednesday night at 7:30pm ET on Google+ Hangouts.
Join us every Wednesday night at 8pm ET for Ask an Engineer!
Learn resistor values with Mho’s Resistance or get the best electronics calculator for engineers “Circuit Playground” – Adafruit’s Apps!
Maker Business — PBS Kids releases baby’s first HDMI dongle
Wearables — Spray on weather
Electronics — Switch Mode Power
Biohacking — FindAir One – Monitor Your Asthma
Sorry, the comment form is closed at this time.