In a pinch I typically use a Voltage Divider and with a couple of Diodes you can drop the voltage slightly to achieve 5 Volts. This way I can have a positive 12 volt rail and end up with two 5 Volts rails plus and minus. The diodes are used to drop the voltage since a voltage divider with say a couple of 10K resistors will divide the Voltage to 6 Volts and a typical silicone Diode such as a 1n4001 will have a .76 forward Voltage drop. Most TTL devices can handle up to a maximum of 5.5Volts but always check the Datasheet of the DUT.
If you want a way of generating a negative voltage with only a single rail you can look at our Negative Voltage Generator kit. That looks at capacitor coupling and a diode arrangement coupled with a 555 oscillator!
Valves. I'm learning how to make stuff with Valves and they're supposed to have a negative grid bias. Still have little to no idea how your supposed to then modulate that bias with the signal you want amplified! 😫
@@backofficeshow I may have a growing obsession... Technically "they're just like big transistors" Except the base (grid) takes negative volts (mostly) And it always inverts. And there's up to three bases. But I'm starting to get that "negative volts" is a _really_ bad description and "lower potential" is what it should be called. So the grid (base) has to be lower potential than the cathode (emitter)
@@backofficeshow, You know strangely enough when i watched this, i was only just watching the other day a GadgetUK164 vid testing Amiga ram using a diagnostic rom, and straight away i thought of exactly what you are going to build, this would save a lot of messing about and time for testing the good olde ram from these retro computers, rather than desoldering a chip, then powering up the computer to run the diagnostics again to see if the ram is still bad, great idea and i will be watching to see what you come up with, good luck with it :)
It’s impossible to derive the 12v from a 5v I put but yea i fell you Ive been frustrated by having to deal with cable mania because of multiple power sources
I saw that which confuses me even more. Also, why did he connect the IN on his 7905 to ground on his arduino?! It is connected to the positive rail. Im so confused.
this video is one of those rare "the EXACT answer to the weird question I have" situations! thanks so much!
You are welcome!
In a pinch I typically use a Voltage Divider and with a couple of Diodes you can drop the voltage slightly to achieve 5 Volts. This way I can have a positive 12 volt rail and end up with two 5 Volts rails plus and minus. The diodes are used to drop the voltage since a voltage divider with say a couple of 10K resistors will divide the Voltage to 6 Volts and a typical silicone Diode such as a 1n4001 will have a .76 forward Voltage drop. Most TTL devices can handle up to a maximum of 5.5Volts but always check the Datasheet of the DUT.
I'll definitely need to try this, always have diodes knocking around
If you want a way of generating a negative voltage with only a single rail you can look at our Negative Voltage Generator kit. That looks at capacitor coupling and a diode arrangement coupled with a 555 oscillator!
I'll look at any kit I am sent 😂
Valves.
I'm learning how to make stuff with Valves and they're supposed to have a negative grid bias.
Still have little to no idea how your supposed to then modulate that bias with the signal you want amplified! 😫
My knowledge of valves is so superficial they may as well be an alien technology to me 😂
@@backofficeshow
I may have a growing obsession...
Technically "they're just like big transistors"
Except the base (grid) takes negative volts (mostly)
And it always inverts.
And there's up to three bases.
But I'm starting to get that "negative volts" is a _really_ bad description and "lower potential" is what it should be called.
So the grid (base) has to be lower potential than the cathode (emitter)
@@MostlyPennyCat that makes a lot more sense thinking of them that way!
Got it it's like a voltage regulator, pre regulated too a serton drop
Hi, the MAX232 IC generates a +/- 8.5v out from 5 volts, not sure what current you'd get from them though, love your channel by the way.
It's probably an expensive way to derive it 😂
@@backofficeshow, You know strangely enough when i watched this, i was only just watching the other day a GadgetUK164 vid testing Amiga ram using a diagnostic rom, and straight away i thought of exactly what you are going to build, this would save a lot of messing about and time for testing the good olde ram from these retro computers, rather than desoldering a chip, then powering up the computer to run the diagnostics again to see if the ram is still bad, great idea and i will be watching to see what you come up with, good luck with it :)
It’s impossible to derive the 12v from a 5v I put but yea i fell you Ive been frustrated by having to deal with cable mania because of multiple power sources
How about a boost converter?
I have a negative voltage on the 12 volt line of the video card where to look for the problem?
any ideas
Check your power supply
You connect ground wire with positive 9 volt
how to get -12v
Two 12v batteries in the same way
Technically interesting, but I still wonder why someone wants to create negative voltage instead of inverting the voltage...
Because in certainrequirements you need both + 5v and - 5v at the same time and it's tricky
@@backofficeshow Guess this is correct, but it confuses me every time. Maybe someday I'll get to a point in engineering, where I find it useful :)
4116 tester?
Yeah, my Kingdom for a 4116 RAM tester
max660m will do this job
Trying to fool putting neg probe to positive
I saw that which confuses me even more. Also, why did he connect the IN on his 7905 to ground on his arduino?! It is connected to the positive rail. Im so confused.