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Battery Board Assembly

Battery Board Notes

The battery board plugs into the mainboard and basically just provides power. Running at full power (both RF channels on at all times), the draw is 650mA from 3.7V.

There are 2 board designs available for download, one with a Li-ion battery (nicer, smaller, more expensive) and one for AAA batteries (more basic, cheaper but less convenient). @ 3.7V the current draw is 650mA, at 5V its 500mA so most small batteries will give you about 1 hr of runtime (unless you go for a large li-ion on the order of 1.4Ah which will give you around 2hrs).

  • Any Lithium Ion battery is acceptable, although one with built in protection circuitry (cell phone batteries for example) is safest (li-ion batteries can explode and/or be permanently damaged by overuse!) You can buy protection circuit boards from batteryspace (see link above)
  • Since li-ion charging is delicate and chargers are hard to come by, the circuitry has been included. For the AAA version, you're expected to take the batteries out to recharge/replace them.
  • LiIon battery charging is accomplished thru either the 4mm DC jack or the USB connector.
  • The DC jack is a standard cellphone/PDA/handheld connector, make sure the adaptor is positive tip and can supply more than 400mA. If you leave out the DC jack, solder the RING pad to the RING-SWITCH pad as the jack connects them internally by default! If the adaptor can supply 750mA or more you can run the jammer directly from wall current! However, make sure that Rsense is ~0.1ohm so that you are drawing enough energy.
  • If you're not using the USB-port debugging console (say you have a spectrum analyzer or you're making a bunch and reusing one board multiple times or have a ttl-serial converter) then you can leave out the FTDI chip (and USB connector)
  • If you're planning to power from some other source note that since Vin has to be boosted to 5V the voltage input should be 3.5V-5V.

Parts List - Li-ion/Li-poly Battery/Charger Pack

Part no.NameDescriptionDistributorQtyCostTotal
Battery-3.7V/1.2Ah Lithium Ion or Lithium Polymer batteryBattery Space (for example)1~$8~$8
Battery Protection Circuit-Circuitry to keep battery safe (optional but recommended)Battery Space1$1.30$1.30
*LM3622M-4.2IC1Battery charger chip for 3.7V lithium batteryDigikey Sample1$2.64$2.64
Hirose UX60-MB-5ST or *Molex 54819-0572J1Mini-B USB connector (SMT)Digikey Mouser Sample1$0.96$0.96
163-2217J21.7mm x 5.2mm SMT DC power jackMouser1$0.77$0.77
STN749Q1PNP 1A power transistor (SOT223)Digikey1$0.79$0.79
FT232RLIC2USB/ttl interface chip (optional)Mouser1$0.30$0.30
SS14 (for example)D1Schottky Diode (at least 1A/20V)Mouser Digikey1$0.16$0.16
LTST-S320GKTLED1LED (1206) any really, but the recommended one is right-angle mountDigikey1$0.16$0.16
UWX1C470MCL1GBC1Input power filter capacitor (47uF/16V minimum)Mouser1$0.18$0.18
B45197A1157K409 (tantalum) UWT0J221MCL1GB (electrolytic)C2Battery filter capacitor (100uF/6.3V minimum)Digikey, Mouser1$0.28$0.28
0.1uF 1206 ceramic capacitorC3- C7High frequency bypass capacitor (~.1uF 16V minimum)Mouser5$0.08$0.40
0.22 1/4W resistor in 1206 pkgR1Changer current sense resistor 0.22ohm allows ~450mA charge current which is the USB max.Digikey, Mouser1$0.32$0.32
2K 1/4W resistor in 1206 pkgR2LED choke resistor (~1K depending on LED and brightness)Mouser1$0.08$0.08

* Can be sampled for free at low quantities

Parts List - AAA Battery Pack

Part # & DatasheetsNameDescriptionDistributorQtyCostTotal
Batteries3 alkaline AAA BatteriesAnywhere3$0.50$1.50
Batteries(alt.)3 NiMH rechargable AAA batteriesBattery Space (for example or Radioshack, etc3$1.25~$3.75
12BH431P3 AAA battery holder Digikey Mouser1$0.89$0.89
Hirose UX60-MB-5ST or *Molex 54819-0572J1Mini-B USB connector (SMT)Digikey Mouser Sample1$0.96$0.96
FT232RLIC2USB/ttl interface chip (optional)Mouser1$4.10$4.10
B45197A1157K409(tantalum) UWT0J221MCL1GB(electrolytic)C2Battery filter capacitor (100uF/6.3V minimum)Digikey Mouser1$0.28$0.28
0.1uF 1206 ceramic capacitorC4-C7High frequency bypass capacitor (~.1uF 16V minimum)Mouser5$0.08$0.40


Place the PCB in your vise. For this assembly diagram I will use the lithium ion board, the AAA board is easier.
Solder in the DC jack and the FTDI chip. Solderpaste is suggested here.
Solder in the USB jack. You can now test whether this works by plugging it into a computer.
Solder in the rest of the components, the low power charging circuitry is not necessary.
If you are using a battery without protection circuitry, attach it. Solder in the battery. The left pad is + and the right pad is -.
/home/ladyada/public_html/wiki/data/pages/wavebubble/battery.txt · Last modified: 2016/01/28 18:05 (external edit)