SkydivinGirl
Retro Girl
Hello fellow geeks!
As you may have seen in my Commodore PC10-III thread, I installed a 6V battery pack to bypass some leaked acid damage for the power line on the realtime clock. Wiring the battery pack's positive line to the power pin on the chip worked great, but I think there are other things pulling the voltage down and running the batteries down.
According to the RTC chip specs, the chip can go into low power mode needing only 2V to operate. Standard operating mode is 5V with a maximum of 6V. After only a short amount of time (a week to a week and a half), my 6V power pack was only showing 2V at the clock with the system turned off.
So, how do I go about fixing this problem? I'm thinking that I can cut the trace that connects the clock's power pin to the main board. After that, I can put in a 3V battery with a diode for standby mode but also run 5V from another point on the board to the clock's power pin for when the computer is powered. I think this will work, but I have a few quick questions before doing this.
1. Should I put another diode between the 5V jumper wire and the clock's power pin? The reason I think I might want to do that is to keep the battery from sending power back along the jumper to other parts of the motherboard when the computer is turned off.
2. When the computer is turned on, it will effectively have two power sources (3V from the battery and 5V from the jumper). What actually happens in this situation?
3. Am I going about the completely wrong? If so, what should I do?
Thanks for your help!
Heather
As you may have seen in my Commodore PC10-III thread, I installed a 6V battery pack to bypass some leaked acid damage for the power line on the realtime clock. Wiring the battery pack's positive line to the power pin on the chip worked great, but I think there are other things pulling the voltage down and running the batteries down.
According to the RTC chip specs, the chip can go into low power mode needing only 2V to operate. Standard operating mode is 5V with a maximum of 6V. After only a short amount of time (a week to a week and a half), my 6V power pack was only showing 2V at the clock with the system turned off.
So, how do I go about fixing this problem? I'm thinking that I can cut the trace that connects the clock's power pin to the main board. After that, I can put in a 3V battery with a diode for standby mode but also run 5V from another point on the board to the clock's power pin for when the computer is powered. I think this will work, but I have a few quick questions before doing this.
1. Should I put another diode between the 5V jumper wire and the clock's power pin? The reason I think I might want to do that is to keep the battery from sending power back along the jumper to other parts of the motherboard when the computer is turned off.
2. When the computer is turned on, it will effectively have two power sources (3V from the battery and 5V from the jumper). What actually happens in this situation?
3. Am I going about the completely wrong? If so, what should I do?
Thanks for your help!
Heather