Tuesday, July 28, 2009

Solar charger

Sunday I was testing a new schematic for the airband (or anyother band) receiver...again....it is based on a converter from 144 to 28Mhz so I set the IF of the Si570 board to 28 connected the output to my HF receiver and to check if I got some real transmission I left the TM-D700 on the same frequency that I was listening on the converter that way I could "see"(on the D700 s-meter) real transmission and ear the same on the converter (hopefuly) unfortunatly when I left the shack I forgot to disconnect the TM-D700, both the TM-D700 and my TS-50 are powered by a small solar panel and a batery, result: today when I went to the shack the power on the battery was 8v.... so did no test today.
Here's the solar instalation description:

A small solar panel (I think it's around 12w and 18v) a charge controler (a simple based LM317 13.80V regulable power supply, batery is 13.8 nominal and the LM is set for 13.99).
The design is similar to this ones except the bridge rectifier and transformer were removed since the input power comes from the solar panel . Batery is a car type (cheaper and will do the job) of 45Ah:


This allows me to be an full afternoon with both radios on althoug it can't hold an full day since the discharg rate is higher than the charge one and I never optimized the charger or the solar pannel angle and orientation. Anyhow it's a nice backup system.

Some photos:

The solar panel (bellow is the airband antenna, it's temporary :)):

The charger (yes, it is Tuna fish in vegetable oil):

The charge meter (never gets more thant 200mA, the meter was laying around in the shack so no need to put another one):

The battery (I move the battery a litle bit from time to time to don't let the lead sulfit settle in the botton and short the batery life, it is working for around 4 years):


Anonymous said...

Thanks for sharing this precious information!
Solar Converters

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