OpenBCM V1.07b12 (Linux)

Packet Radio Mailbox

DB0FHN

[JN59NK Nuernberg]

 Login: GUEST





  
G8MNY  > TECH     11.08.04 18:45l 46 Lines 1721 Bytes #999 (0) @ WW
BID : 5115_GB7CIP
Read: DL4DBX GUEST DG6OU OE7FMI
Subj: FT290/690/790 DC Power mod.
Path: DB0FHN<DB0FOR<DB0SIF<DB0EA<DB0RES<ON0AR<ZL2TZE<GB7YFS<GB7CIP
Sent: 040811/0850Z @:GB7CIP.#32.GBR.EU #:5115 [Caterham] $:5115_GB7CIP
From: G8MNY@GB7CIP.#32.GBR.EU
To  : TECH@WW

By G8MNY

WHATS WRONG
1/ The original external power jack uses the dangerous +ve outer standard
   so that the when connected to other kit there is a risk of shorting.

2/ The jack switch is supposed to disconnect the +ve battery lead when the
   external power is applied. This depends very much on the make/type of plug
   used, & it is easy to draw high current though the battery pack & cook
   the cells & holder & possably he rig!

3/ An reverse polarity idiot diode is provided, but the the -ve connection. So
   if the the rig is connected to other kit (eg a powered speech processor) the
   protection is negated, and the mic lead now carries the rig current!

4/ The Plugtop raw charging (hummy battery) is via a 2.5mm, that shorts out
   the charger when plugged in/out. There is no idication that the charger is
   not being shorted out!


Here is my circuit that solves most of these problems...

+ve centre 
power Jack  (oÄÄoÄoÄÄÄÄÄÄÄÄÄÄÄÄÂÄÄÄÄÄÄ´>ÃÄÄÄÄÄÄÂÄÄÄ>Rig supply
Switch      ³ wire    2.5mm   LAMP             ³
unused      ³ fuse    charge>ÄÄÁÄÄ´>ÃÄÄÂÄÄ´>ÃÄÄ´
            ³ 1A         ³             ³       ³+
            ³            ³     NICAD ÄÄÁÄÄ    ===
            ³            ³     PACK   ===      ³1000u
           _³_          _³_           _³_     _³_
          ////         ////          ////    ////

It uses most of the existing components. The Lamp is a wire ended fairy light
that provides low trickle current when the rig is 10-14V powered. 
Some rigs also include a small 1000uF 16v by the jacks. The 12V jack is
remarked with a +ve centre with a RED felt pen.



Why Don't U send an interesting bul?
/QSL
73 De John, G8MNY @ GB7CIP


Read previous mail | Read next mail


 17.03.2025 05:32:46lGo back Go up