My first (useful) circuit, probably something wrong here =)

First off, thanks in advance you guys were awesome on code help and apologies if this is posted in the wrong area.

What I'm trying to do:

Use a transistor as a relay. The DPST kills the whole circuit / LED goes on when circuit is live. This is 1 of 6 that connect to the arduino, just drew 1 other 5 are on the same board / identical but different pins.

0) Disregard Ohms / parts numbers haven't figured out correct numbers yet 1) Can all grounds connect to the same point? 2) Worried about voltage drop on the LED's if 6 are coming off the same 5v or how to deal with some being on / off. Basically not sure on that part. 3) Edit, if LED's are backwards etc will flip that when I put it in. Same with transistor.

LEDs are backward. The Led in the transistor cct. needs a series resistor. The Base resistor is too small try 1K.

What are you trying to do?

Can all grounds connect to the same point?

They not only can, but they [u]should[/u] all be connected.

You need to look at some schematics. There are some standard formats. In particular, led cathodes are
generally shown pointing toward the bottom of the page. The exception is when there multiple leds
coming off the pins of driver chip or uC to the left or to the right. Also, transistors are almost ALWAYS
drawn with the collector/ emitter oriented in the vertical axis and the base in the horizonal axis. The
base is usually shown facing the left. The exception is in a circuit like an H-bridge where there are pairs
of transistors, two on the left, and two on the right. Naturally the base of the transistors on the right
points toward the right. If there are several transistors but they are not part of a complimentary circuit
like an H-bridge, they are placed in a row with all the bases pointing to toward the left. In either case,
the collector is always pointing toward the top of the page and the emitter toward the bottom. The
exception is a linear power supply series pass transistor where the collector points toward the left, the
emitter toward the right and the base points toward the bottom. Your schematic looks like it was drawn
by someone who has never seen a schematic before. (just thought you should know)

Thanks for the feedback. I was new to using the software and can make all those changes you suggested.

Also what software do you suggest for drawing schematics?

Regarding use, I'm essentially making a remote trigger with lights for a paintball gun.

I haven't looked at any schematics in probably 10 years or drawn one either so just getting back in to it. Thanks again.

Jered

Also what software do you suggest for drawing schematics?

Pencil, paper and cell phone to photograph it. If you want to (RE)-learn drawing schematics, there's no substitute for actually doing it. I can't help you with the software question. I used ORCAD back in the day and currently at work but don't have a my own copy at home so I use pen & paper. (don't need a pencil because I don't make mistakes , ha ha... :D )

raschemmel: Pencil, paper and cell phone to photograph it. If you want to (RE)-learn drawing schematics, there's no substitute for actually doing it. I can't help you with the software question. I used ORCAD back in the day and currently at work but don't have a my own copy at home so I use pen & paper. (don't need a pencil because I don't make mistakes , ha ha... :D )

Thanks I started with pen and paper but then used some online software because I thought I could make it nicer. I also broke the only pen I found in the house... too digital these days.

I'll go back to pen and paper and look up some rules / symbols on schematics.

Let me pretty it up and I'll show you guys round 2.

Thanks again.

The idea is that all circuit schematics should start on a restaurant or or cocktail napkin so you have to be able to actually draw it (ha ha).

Alright, little prettier now.

I'm wondering if there's a way I can use a SPST instead of DPST. The goal is to have two LEDs in this circuit. One lights everytime the relay closes (input from the arduino). The second one is lit when the circuit is powered (switch closed).

Really excited to be getting back in to electronics.

raschemmel: The idea is that all circuit schematics should start on a restaurant or or cocktail napkin so you have to be able to actually draw it (ha ha).

Next one on a napkin for sure!

Oh dear ! Where's the current limiting resistors for the leds ? (!)

FYI, Schematic is better but Google transistor symbol and use that.