Updated: 6.29.02


Power Supply

Power Supply: 19 A-hr, dual 12v outlets for dew heaters and Meade 18v outlet. The main switch at the top left is actually an on-off-on switch. The top position (ON) applies 12v to the meter (which has it's own set of switches for the meter and light), the 12v automotive outlets and to the internal 12-to-18v inverter. The inverter has its own switch at the bottom left next to the Meade-type power jack. I have the same inverter that is used in the Kendricks 18v 34 A-hr power supply and it is fused at the input (4A). The main switch also has an off position in the middle and connects the charger to the battery in the down position (CHG position). Two automotive style 12v outlets are included for 110v power inverters and the Kendricks Dew Heating system. You can see the detachable 120v cord at the bottom that powers the charging unit. Many trips to Radio Shack were made for this effort, but the resulting portability was well worth it. Overall, the unit measures about 7.5"x10" and weighs on the order of 18 lbs. Baltic birch


plywood was used for the construction and was chosen due to the lack of voids in the layers. I researched the possibility of having a custom aluminum face plate made, but a one-of-a-kind plate would have been over $130.

The digital voltmeter from Radio Shack required a bit of work to install. Soldering across various jumpers were required to set the decimal place, the range, the units (v, T, A, etc.) and the type of meter (ammeter, voltmeter, etc.). I also had to install a voltage divider to supply the 9v for unit's power input and 5v to the backlight. A switch to power the meter (labelled MTR) and a light switch (LGT) have also been wired in. I did this to have the option of shutting down the meter which draws 20mA by itself.

The detachable plug is shown at the bottom and utilizes a cord typically used for computer power supplies.