I'm installing an off-board battery harness in one of my machines. The pinrepair.com website says to use three AA batteries preferably with a 1N5817 blocking diode in circuit to cut the batteries off before they completely die and begin to leak. I only have a few 1N4730 diodes on hand and wanted to know if these would be an acceptable substitute for 1N5817. My knowledge of diodes is limited so I'm not really sure what to look for here.
Most of us are using a 1N4001 which is rated at 50V 1A, the 1N4730 is only rated at 3.7V 1A which is very borderline IMO.
-Mike
So, I looked up the datasheet, and I'm going to say, no; it will not work.
The 1N4730 is a Zener Diode, which means that it will act as a blocking diode up until a certain reverse voltage is reached. The datasheet says that its zener voltage range is up to 3.9 volts (3 AA batteries would exceed that voltage, and allow a reverse voltage to pass through if the CPU were to try to "charge" them).
I'd look for a proper blocking diode like Grizlyrig has mentioned.
Quoted from Grizlyrig:1N4730 is only rated at 3.7V 1A
Did more looking and I was wrong on the amps..it's only rated at 200ma before it swings open, so you cannot use it at all for this application.
-Mike
1N4730 is probably a zener diode. you dont want that.
use a standard rectifier or signal diode. like 1n4001 to 1n4007. 1n4148 etc.
Get the 1N4004 they are cheap and will cover 90%+ of you pinball diode needs. Last time I stocked I think I got them from GPE at 20 for 1$ or something like that.
One final question here, is it ok to install a battery harness with an 1N4004 on a 6803 machine to replace the original nimh/nicd battery? I figure there is a reverse voltage applied to the battery circuit to charge the original battery while the machine is turned on. Will this have any ill effect on alkaline's in series with a 1N4004?
in 6803 you need a diode when using a non rechargeable batteries to block the power supply +5v from getting at the batteries.
Two options. Put the diode with the battery pack or change the current limiting resistor on the PCB. You can do a 4 terminal battery pack, use 3 batteries, and have the block diode across the fourth battery terminal.
$15 also buys use a NVRAM chip which holds memory virtually forever with no batteries. plug and play in 6803 games (6116 NVRAM).
Quoted from barakandl:$15 also buys use a NVRAM chip which holds memory virtually forever with no batteries. plug and play in 6803 games (6116 NVRAM).
Seriously, why does anyone screw with batteries anymore? Just put Barakandl's NVRAM in there & forget it.
Extremely quick shipping, good vendor, active on Pinside.
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