It’s the do-It-yourselfer’s model of Murphy’s Regulation: Each time you have to sink some powerful screws, the battery in your cordless screwdriver is lifeless. So that you do the one factor you possibly can: plug the screwdriver into an outlet and endure the a number of hours it takes to recharge. However why wait all day? Substitute these plodding rechargeable batteries with large-storage tremendous capacitors that energy up by way of your pc’s USB port, and you’ll shorten recharge time to lower than a minute and a half. Tremendous caps each retailer and ship power rapidly, so that you gained’t get almost the endurance of a battery, however every cost will get you thru a few screws—excellent for fast tightening jobs. Coleman now sells a fast-charge mannequin that lasts a bit longer, however our DIY model is half the fee. Now your solely downside will probably be determining what to do with all that additional time in your palms.
H2WHOA! Earlier than closing the screwdriver, examine all connections with a multimeter whereas test-charging and discharging the capacitors. Modding a screwdriver on this means could void its guarantee.
TIME: 5 HOURS
DIFFICULTY: MODERATELY DIFFICULT
- 3.6V Cordless rechargeable screwdriver (Harbor Freight Instruments #91332; $13)
- Breakout board for USB mini B (SparkFun Electronics #BOB-08401; $2)
- (4) Tremendous capacitor 10F 2.5V (SparkFun Electronics #COM-00746; $5)
- Hookup wire (RadioShack #278-1223; $6)
Contained in the On the spot-Cost Screwdriver
1. Open up the screwdriver and take away the battery pack.
2. Desolder the barrel-shaped cost connector and the battery connection clip from the screwdriver’s circuit board. Solder a crimson wire from the breakout board’s VCC conductor to the optimistic (+) pad on the circuit board, and a black wire between the GND connections of the 2 boards.
3. Join two capacitors in collection (optimistic lead of 1 soldered to detrimental lead of the opposite). Repeat with one other pair. Then be part of the 2 units collectively in parallel (optimistic to optimistic, detrimental to detrimental).
4. Solder the optimistic leads out of your energy pack to the 2 crimson wires from the change and the circuit board, and the pack’s detrimental results in the 2 black wires.
5. Widen the cost port on the screwdriver case giant sufficient to entry a mini B USB cable. Fasten the breakout board to the within of the screwdriver. Line up the port with the opening, and reassemble the case.
6. Plug the screwdriver right into a USB port in your pc. The crimson LED ought to glow—when it goes out, in about 90 seconds, the screwdriver is charged.
Get pleasure from your new “fast cost” screwdriver.