You can use trimmer pot since you are building just 5V regulator if you wanted more voltage i'd lose pot.

I thought I wanted just 5V, but now you turned me on to the *world of many voltages" might come in handy to change to a value closer to 10V. most LEDs at yebo are 10V, so there's atleast one reason to go for the pot solution!

 

I thought I wanted just 5V, but now you turned me on to the *world of many voltages" might come in handy to change to a value closer to 10V. most LEDs at yebo are 10V, so there's atleast one reason to go for the pot solution!

What kind of led works on 10V? Are you are powering led strips?

 

10K is overkill 58.068V, 1K is 6.932 but 4700 is 27.955 which will work

 

What kind of led works on 10V? Are you are powering led strips?

Nope, why what do you think it should be? (Oh, its upto 10V)

 

That will not do for TTL logic circuitry.

You need the +5 volts to be as exact as you can make it.
TTL is more sensitive to overvoltage. 5.1 is within range but too close to the TTL range of 4.75V - 5.25V supply.
Further the 5V provides the reference level for the logic pulses.

By contrast the CMOS voltage range is +3V to +15V

This is a good opportunity to practise your series and parallel skils to get your resistors closer in combination, though most practical people would use a trimpot and set the final value to give correct output with a voltmeter.

Why do people keep saying that the CMOS voltage range is +3V to +15V?

The allowable voltage range is highly dependent on the CMOS family. Today, very few families can tolerate 15V and many are designed to work at 2.5V or lower. For example, the 74HC family, which is hardly new, has a max Vcc of 7V and is spec'ed at Vcc levels of 2V, 4.5V and 6V.

Making blanket statements about CMOS being able to run up to +15V is just encouraging people to let the magic smoke out of modern logic parts.

 

Cellphone (and other) chargers are not usually suitable without modification as they are not true DC.

Have you tried downloading my attachment and viewing it full size? The underlying pic is quite large and easier to see that way.

This is nonsense. I use cellphone chargers that I buy for $1 at flea markets for microprocessor projects. Every one of they put out rock solid 5V DC. I was surprised at how good they looked on a scope.

Bob

 

This is nonsense. I use cellphone chargers that I buy for $1 at flea markets for microprocessor projects. Every one of they put out rock solid 5V DC. I was surprised at how good they looked on a scope.

Bob

Phew! I didn't buy the chargers for nothing! I was very worried there for a moment! Thx Bob!

 

This is nonsense. I use cellphone chargers that I buy for $1 at flea markets for microprocessor projects. Every one of they put out rock solid 5V DC. I was surprised at how good they looked on a scope.

Bob

Bob, if you say microprocessor projects, how much current would I need for standard messing about with digital electronics, or are there no easy answer?

 

There is no easy answer, but 1A should last you a long time.

The things that you are likely to use that would consume more than that are things like motors or high power LEDs.

I should correct that, microprocessor -> microcontroller.
The microcontrollers themselves use only a few milliamps. The highest powered one I use uses 60mA at top speed.

Bob

 

There is no easy answer, but 1A should last you a long time.

The things that you are likely to use that would consume more than that are things like motors or high power LEDs.

I should correct that, microprocessor -> microcontroller.
The microcontrollers themselves use only a few milliamps. The highest powered one I use uses 60mA at top speed.

Bob

And with this 1A limit, how easy is it to add another psu, like use one psu for 5v and a 12V psu for the rest, ok so it's a project that requires two wall sockets, but hey, I'm a student, not a fabricator

 

Current usage of microcontroller is very small,its like 60 mA at 16mhz for atmega ones and its going to depend on how much stuff you have hooked up on microcontroller.
If you are controlling high power motors they need a separate supply going into the driver IC.

 

Like this then, please feel free to rape my values/ratings, I know it comes from the best sources ;-)

 

Pin 2 of trimmer needs to be connected to ground.You will need a 2200uf capacitor before lm350.Protection diode should be placed above the regulator.

 

Pin 2 of trimmer needs to be connected to ground.You will need a 2200uf capacitor before lm350.Protection diode should be placed above the regulator.

ofcourse (forgot the diode)

 

which diode? On hand I have (but I'm anyways making a trip to yebo, so I could just buy the correct one) 1n4148,1n4007, and 5* 1n5402 (the other 2 I have 10 of each)

 

studiot, I have 4* MJE3055T already, for the negative part, isn't swopping the polarity on the MJE3055T the same as using a MJE2955T, they're complementary transistors, just the one is npn (3055) and the 2955 is pnp, I'm sure I read something to that effect somewhere?

 

and my 5v 7805 regulator, is that correct?

 

You need 0.1uf cap in front of all 7805 schematics.
Put a protection diode like here:

 

This?

 

this heatsink? http://www.mantech.co.za/ProductInfo.aspx?Item=14M5419