CDTV realtime battery backup

[simon_m74]

Hi all,

I`ve been looking at desiging a CDTV battery backup for its clock - so that if it looses the mains supply - it will keep the time.

Easy way....
Snip leg 18 on the RTC chip, then connect that to a pcb I`m working on, that will supply 5v when powered, or battery backup.

Hard way...(cant be sure if this will work yet)
Add a PCB, by piggy-backing LC6554C, adding a SECOND clock chip, in hope it sycronizes with the CDTV rtc, then when power is resumed, it sends clock data to the onboard one.

half-way....
Snip leg on onboard rtc, add a new one as above.

What are peoples thoughts ?

 

[PRS]

Desolder the LC6554c and place a socket in its place. Then do the mod with pin 18…

 

[simon_m74]

Desolder the LC6554c and place a socket in its place. Then do the mod with pin 18…

Lucky the LC6554C is already in a socket.
Will still need to desolder/disconnect pin 18 - to remove power from the original RTC

 

[Bandit0r]

Nice thought, but sorry have to say:

doesn't this post belong to a AmiOracle or General chat?

 

[simon_m74]

Trying to get interest and ideas of what to make - then once ready, I`ll sell on here

 

[Hannibal]

- socket rtc
- add PCB between socket and rtc that resembles what is happening on a3000/4000 (without the charging part)

What's the point of aging a second rtc?

 

[simon_m74]

The only idea of a second rtc was to fully replace the one onboard to power it - but I`m going to abandon that.
Plan is option 1.
I`ll design a PCB (with usage like A3000) that controls the power to the RTC - this is the minimal `alteration` to the CDTV - with just one pin being disconnected and re-routed.

Can people please PM me with any interest for one.

I`ll finish the design tonight

 

[simon_m74]

The design is sorted....
Tested working!
I`ll start a new post tonight