Thank you. I knew that. I built the memory card switcher box and it works but my Katana cards still light up dimly when there is no vcc going to them. I have all the cards on parallel with everything except for 7v(cuz it's not used) and 3v and data(cuz those are the ones I'm switching)
I tried putting a transistor inline with the ground of the Katana to also cut ground when there is no 3v(have that hooked up to the base of the transistor with a 3kohm resistor) the collector hooked up to the gnd of the mc and the emiter hooked up to the ground. However, what I find is that the ground is ALWAYS active. What is wrong with my circuit? I will try to draw you a diagram so if you can PLEASE help me!!!???
S means it's switched at my 2 pole six position rotary switch
So basically S denotes entire column as switchable
P means it's parallel
So basically P denotes that all cards/slots share same wire
- is for the 7v since I don't use that at all so it's neither parallel nor switched
The following are labels for pins (notice dat next to cmd on first two columns)
dc 7g3 sca
am vnv elc
td d 1ok
██ ██ ███
MC_interface_cable SP -PS PPP
MCslot1 DC 7G3 SCA
MCslot2 DC 7G3 SCA
MCslot3 DC 7G3 SCA
internal MC1 DC 7G3 SCA
internal MC2 DC 7G3 SCA
internal MC3 DC 7G3 SCA
Now, this "works" to save and load but when the rotary switch is not selected to
one of the slots with the Katana 32mb card(with lights to show which pages is
selected via a small push button they built into the card) then the page lights
are still lit. That is my "problem". They are getting power from all data/serial
lines (not 3v cuz that's switched off of course) and using the same GND. If I can
switch that GND, that'd be great but I don't want to add more switches to the box.
I want it to look clean and only use the rotary knob.
However, when I attach a transistor like so:
Collector to MC slot1 ground (just mcslot1 for now to test)
Base to 3kohm resistor to MC slot 3v
Emitter to MC_interface_cable GND
The slots gnd should switch off when there is no 3v going to it's base
(when the rotary is switched to say slot 3 or 2 etc...)
But it IS still "on". There is still a ground and the katana's lights still
flicker as you load or save with another card in the switcher.
Did I wire the transistor incorrectly or is it a broken transistor?