Message 27157 in TECH.WW
From: G8MNY
Date: Mon, 03 Aug 26 06:33:00 Z
Newsgroups: TECH.WW
Subject: 1A Float/charging Pb Acid Batt
Message-ID: <995_GB7CIP>
Path: N2MH4|GB7BED|VA2RIZ|VA7RBP|VE3KPG|GB7CIP
R:260803/0637Z 34791@N2MH4.#SENC.NC.USA.NOAM LinBPQ6.0.24
R:260803/0637Z 15292@GB7BED.#21.GBR.EU LinBPQ6.0.25
R:260803/0636Z 3691@VA2RIZ.#LAN.QC.CAN.NOAM LinBPQ6.0.25
R:260803/0636Z 43295@VA7RBP.#SCBC.BC.CAN.NOAM LinBPQ6.0.25
R:260803/0636Z 27885@VE3KPG.#ECON.ON.CAN.NOAM BPQ6.0.25
R:260803/0633Z @:GB7CIP.#32.GBR.EURO #:995 [Caterham Surrey GBR] $:995_GB7CIP
From: G8MNY@GB7CIP.#32.GBR.EURO
To : TECH@WW
By G8MNY (Updated Oct 05)
(8 Bit ASCII graphics use code page 437 or 850, Terminal Font)
Here are 2 simply circuits for small discharge current batteries.
1/ On Insulated Heatsink
Voltage set by Zener + Reg - output diode loss. 13.5V recommended for floating
Gel & sealed types. 13.8V for wet ones that can be topped up. 14.5V for
charging after discharge, but not left on that voltage!
Current is limited to a peak of 1A. With no I/P smoothing C there will be hum
on the charging current & the battery voltage may not be suitable for floating
with electronic loads. The output diode voltage drop lets the PNP light the LED
when the diode has 0.7V across it. The diode also protects the regulator from
reverse voltage if the PSU is off when connected to a live battery.
2/ Add a series R in the common leg. Most makes of regulator put about 50uA
constant current down the common leg, so a small R can uplift the voltage.
On Insulated Heatsink
BRIDGE 30V=== Multi 10k === Output
I have used this one for many years to float my paket station on a 5AH gel cell
battery. Via a fused lead it powers a PacCom TNC220, a FT290R(i), & 30W PA,
peak Tx current 8A, Rx 500mA leaving just 500mA to charge for the short packet
Tx time.
Why Don't U send an interesting bul?
73 De John, G8MNY @ GB7CIP
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