What to buy?

[Mark68]

I was banned and now I've only just rediscovered this thread.

Here's a picture of the whole thing, see this thread for more information.

I saw the banned under your name...but when I went to your profile (stalking you) It showed the last time you were on.....and both days said you were on earlier in the day. What did you get banned for....seeing your post #s I am thinking that banning you is probably not a good idea for the site...you are obviously an asset. Anyways...glad your back. Here's my questions so far.

1)How big should I make the board dim....yours in the picture looks like a good size.

2)Is this unit that you have in good working order..do you use it, or should it be tweeked?

3.) Should I add the C8 cap in my pcb design?

4.)According to the link you gave me...should I get the 15V-0-15V torroid rated to 2.67A Transformer...? I'm in U.S.

5.) R1 will use a 1/2 watt rating? R2-R6 1/8 watt rating?

6.) I should buy a 2.5kohm pot with a 1/2 watt rating? (R7)

7.) Rating of switch? SPST?

8.)Are these Caps for C1 and C2 good, or do you recommend better? Caps

I am not sure what the triangle is in the schematic...I want to say a rectifier...but I am not sure? According to the link you gave me. D1 should be 2.5A. But what does that mean.....and how do I go about making it.....or do I buy it?

Anything that you can tell me about the rectifier if that's what it is...would be very helpful....it don't look like much to know....but I'm not understanding it? I don't need to understand it....just tell me this diode rating goes here and this one goes there...blah blah...I'll figure it out when I learn to calculate and do the math...which by the way I am trying to learn everyday reading some good electronic books. My time is limited though...I work alot of hours taking care of the family.

K....as you can see, I have been waiting to hear from you for awhile. LOL

Sorry for all the newb questions......it's not laziness I assure you...I'm trying very hard to learn..and spend most my free time learning as much as I can.

By the way.....that last PCB I made that everyone helped me on....came out beautiful. I was very suprised at how well the soldering came out. The pads where so close together I thought for sure I would have a hard time with it. There probably isn't an 1/16 of an inch between some of them...specially around the IC's, yet none are touching ( I used a 10x magnifier to check ), solder is all the way around each lead, and they are nice and shiny. I noticed that in your PCB layout for the bi-polar supply that you used the rectangular pads instead of the round ones..so I will keep that in mind next time I make a board.

Thanks for all your help....and stay un-banned. Glad your Back.

 

[Mark68]

Man oh man i wish I could get someone to help me out with these questions so I can get started

 

[Hero999]

I asked the moderator to move this to the other thread as I would rather not derail this one. Either he hasn't seen my report or doesn't want to move it.

It's late now 12:30 and I'm just off to bed so I'll post a response to your questions, whether or not the moderator moves this, tomorrow.

 

[Mark68]

I asked the moderator to move this to the other thread as I would rather not derail this one. Either he hasn't seen my report or doesn't want to move it.

It's late now 12:30 and I'm just off to bed so I'll post a response to your questions, whether or not the moderator moves this, tomorrow.

I thought about that a few times.....but it seemed to die on it's own any way.

I Will check this thread and the other one....if you choose to respond in the other one on your own.....I will pick up there as well, besides we can always link one or the other for reference sake if the moderator chooses not to move it. Thanks for getting back to me. Much Appreciated.

 

[Hero999]

I saw the banned under your name...but when I went to your profile (stalking you) It showed the last time you were on.....and both days said you were on earlier in the day.

I clicked on the site in my bookmarks and it told me I was banned. The forum software must have notice my IP said I was online, even though I couldn't post.

What did you get banned for....seeing your post #s I am thinking that banning you is probably not a good idea for the site...you are obviously an asset.

A troll was rude to me when I was trying to help so I lost my temper and sent him a rude PM (which contained swearing), which he must've forwarded it on to the moderator.

Anyways...glad your back. Here's my questions so far.

1)How big should I make the board dim....yours in the picture looks like a good size.

The dimensions of my board were 95.5×58mm

I recommend you make your own board rather than using mine.

2)Is this unit that you have in good working order..do you use it, or should it be tweeked?

Mine worked perfectally.

3.) Should I add the C8 cap in my pcb design?

You're better off including it just to be on the safe side.

4.)According to the link you gave me...should I get the 15V-0-15V torroid rated to 2.67A Transformer...?

As long as the transformer is rated to over 2.2A, it will be fine.

5.) R1 will use a 1/2 watt rating? R2-R6 1/8 watt rating?

6.) I should buy a 2.5kohm pot with a 1/2 watt rating? (R7)

The component ratings in the table on page 2 are minimum ratings, you can use any components with an equal or greater maximum rating. For example R7 is specified at 125mW minimum but there's no harm in using a 250mW resistor.

https://www.electro-tech-online.com/custompdfs/2009/08/Bipolar20PSU.pdf

7.) Rating of switch? SPST?

Yes, I forgot to put the switch on the schematic.

The switch needs to be rated for mains voltage.

Use >1A for 120V or >0.5A for 230V power, again these are minimum ratings so if you have a 2A switch rated to 250V then fine.

8.)Are these Caps for C1 and C2 good, or do you recommend better? Caps

40V is more than good enough.

I am not sure what the triangle is in the schematic...I want to say a rectifier...but I am not sure? According to the link you gave me.

That's an op-amp.

D1 should be 2.5A. But what does that mean.....and how do I go about making it.....or do I buy it?

Anything that you can tell me about the rectifier if that's what it is...would be very helpful....it don't look like much to know....but I'm not understanding it? I don't need to understand it....just tell me this diode rating goes here and this one goes there...blah blah...I'll figure it out when I learn to calculate and do the math...which by the way I am trying to learn everyday reading some good electronic books. My time is limited though...I work alot of hours taking care of the family.

It's a bridge rectifier module and needs to be rated to at least 2.5A, you can use discrete diodes or buy it pre-assembled.
**broken link removed**

K....as you can see, I have been waiting to hear from you for awhile. LOL

Sorry for all the newb questions......it's not laziness I assure you...I'm trying very hard to learn..and spend most my free time learning as much as I can.

By the way.....that last PCB I made that everyone helped me on....came out beautiful. I was very suprised at how well the soldering came out. The pads where so close together I thought for sure I would have a hard time with it. There probably isn't an 1/16 of an inch between some of them...specially around the IC's, yet none are touching ( I used a 10x magnifier to check ), solder is all the way around each lead, and they are nice and shiny.

1/16 inch isn't too hard, things get more difficult at 1mm (about 0.04 inches).

I noticed that in your PCB layout for the bi-polar supply that you used the rectangular pads instead of the round ones..so I will keep that in mind next time I make a board

It doesn't make much difference, my latest PCB has all round pads and only uses square pads to indicate pin 1 on the ICs and the negative terminal on capacitors and diodes.

 

[Mark68]

By saying the triangle.....I meant the square. LOL
I think I was thinking of diode shape when I typed it. ( at least I hope )

Better Idea even yet......about the square for pin 1 and negative terminals...I like it!

Still real sketchy on the rectifier.....but I havent had a lot of time to do some research either. I will have some time (I hope) this weekend....and look into it. Any sites you can think of that explains it.....let me know?

Thanks for your answers.....eventhough they may be elementary to you.......they set my mind at ease to begin.......Thanks again.

Probably not the last question......but I got some planning and implementing to do.

 

[Hero999]

A bridge rectifier is nothing fancy, you put AC in and get DC out. The advantage over using a single diode is both positive and negative cycles are used. The DC waveform will have a lot of ripple so a large capacitor is required to smooth the waveform.
Diode bridge - Wikipedia, the free encyclopedia

 

[Mark68]

I'd recommend an LM317 supply.

Your schematic you gave me calls for LM337 and LM217.

What two do you recommend? ....and if different than the schematic...will I have to change other components as well? I am ordering so I want to make sure I get the best components for the project. I can follow a schematic....not calculate. At least not yet.

Is this what I'm looking for? Transformer, Rectifier

 

[Mark68]

k.......I am seriously thinking about purchasing this one right here....just want to make sure it's the right one......I believe the rating would be 2.5...but the voltage is 12-0-12 I can't find 15-0-15 anywhere.....is this ok? **broken link removed** Please get back to me so I can order.

 

[Hero999]

The output voltage needs to be >15V, 12V won't be high enough to give you the full output voltage.

Try looking a transformers with twin 15V secondaries if you can't find one with a centre tap.

I used the LM217, if you can't get hold of it, use the LM317 but change R3 to 82R and R7 to 1k, in this case R7 needs to be rated to ¼W or more.

You need the LM337 for the negative side because it's a negative voltage regulator.