extreme beginner help

tybomb

Joined Jan 23, 2007
17
I'm trying to build this circuit on a breadboard.
I've been learning as much as I can about electricity and circuits but I'm just not getting it. At this point I just need to see it laid out properly so I can even understand what I'm reading. If anyone can give me a little graphical help using the breadboard pic I'd really appreciate it.

tybomb

Joined Jan 23, 2007
17
Thanks for the link. Those diagrams are great. I have that decade counter I think. I've got the components but I'm just lost trying to arrange them properly. I made this graphic to show how I have things arranged. Probably lots of stupid mistakes but thats why I'm here
I circled the parts that are confusing me. (the most).

tybomb

Joined Jan 23, 2007
17
oops I forgot to add in the little wire that connects the two sides of the board between R1 and C2. I've got it but just forgot to put it in the picture. I'm really confused about grounding. I've read about it but I don't understand how you ground something on a bread board. Like at B1 and C2 it shows that it's grounded but I dont understand how. Then at the bottom on connection 13 of the Decade counter it shows that as being grounded yet the wire goes to the same path as the other ones.

tybomb

Joined Jan 23, 2007
17
And why do R3 and SW1 have three connectors on them with no markings showing what they're for and the schematic doesnt explain it either. Obviously they assume people already know what they're doing but........

Spoggles

Joined Dec 2, 2005
67
tybomb

I do not understand YOUR circuit at all. I just sent you the link to show you how to make a working circuit.

Generally switches with 3 leads on them have a Common contact (usually in the center) which connects to the normally open (closes when the switch is "ON"), or the normally closed (opens when the switch is "ON"). It is pretty much up to you as to the way it is hooked up. Variable resistors have 3 leads. The two outside ones are a fixed resistance and the middle lead provides a "tap" so you may 'pick off' a resistance from 0 to whatever the max resistance is.

Hope this helps.

Spoggles

tybomb

Joined Jan 23, 2007
17
Ok. I guess I must have it hooked up pretty close to how it should be since the led is blinking about once per two seconds. I'm still unsure of the potentiometer. Are you saying that the middle lead has to be hooked up in order to set it at a point between the high and low? Hopefully I understood that right. If that's the case then where do I run the middle wire to?
Other then that I just dont understand the grounding part.
1. Where does c2 go? In the scematic it shows the posative end connected to the current and then the other end goes nowhere and shows as being grounded. Does that mean I just plug the negative end in to any empty hole thats not part of the circuit?
2. The battery shows the posative connected to the circuit and the negative going nowhere.
3. The same thing with the wire I put the question mark on. That one shows as being grounded but how?

kubeek

Joined Sep 20, 2005
5,772
The ground symbol means that the device is connected to ground. It is no real ground, but only a thing to make the schematic easier to read.
All the components with ground symbol are connected together.

tybomb

Joined Jan 23, 2007
17
Thanks for the help. I think I may actually have it working properly now. Here's a pic of exactly what I did. If anyone has the time to give it a look I'd appreciate it. There may be some horrendous mistakes.

Circuit operation:

IC1 forms a narrow pulse, 2.5Hz oscillator feeding IC2. This chip generates the various timings for the output pulses. Output is taken at pins 2 & 3 to easily obtain negative going pulses also. Current output is limited to 600µA by R2 and can be regulated from 80 to 600µA by means of R3. The LED flashes every 2 seconds signaling proper operation and can also be used for setting purposes. It can be omitted together with R4, greatly increasing battery life.

hgmjr

Joined Jan 28, 2005
9,027
You are quite the artiste. Very impressive drawing. It is so good that unless I have mis-interpreted the drawing, it would appear that the connection between IC2 pin-13 and ground seems to be missing. This may just be an oversight in your sketch.

hgmjr

tybomb

Joined Jan 23, 2007
17
Yep your right. I forgot to put it in the picture, which incidentally took longer then the actual circuit. lol.
I did the picture because I wanted to make it easy as possible for someone to tell me if I screwed up or not. After all this will be hooked up to my head. I already tried it out for a few minutes and it feels pretty weird. The pulse packs quite a jolt when you crank it up. It's in the same location as I put it in the first picture. Hopefully that was right.

hgmjr

Joined Jan 28, 2005
9,027
Please report back to the forum from time to time to let us know how you are getting along with your CES treatments.

Of course, if your subsequent posts contain mostly jibberish we will be force to conclude that you have done yourself a serious mischief.

hgmjr

kubeek

Joined Sep 20, 2005
5,772
I think that the potentiometer is connected wrong, and the switch too! when you switch the circuit off you shortcircuit the battery.

btw I noticed you use much more wire connections than needed, you can use components with long leads as a wire itself, for example the little red wire from LED to ground can be ommited and the led connected straight to ground.
Another thing is that you should use the red long line for + voltage and the blue one for ground, it is then easier to connect and change.

tybomb

Joined Jan 23, 2007
17
In the picture it seems I have mixed up the two outside wires. They are actually reversed. Is that what you mean? The switch was kind of a trial and error thing. It seems like it's working fine. I can't find any pics showing how they have to be hooked up.

tybomb

Joined Jan 23, 2007
17
I thik I see what you rmean about the switch. I wasnt sure how they are made. If it's in the off position there is a connection going straight from the battery in to the ground? I switched it so the Voltage in is on the opposite end from the ground and it still works. is that right?

tybomb

Joined Jan 23, 2007
17
Actually I looked at the circuit again and I do have the potentiometer hooked up as it is in the picture. I hooked it up according to the diagram I found on this site.
http://www.music.columbia.edu/~douglas/pc1600mod/pc1600mod.sensors.html
Is it hooked up wrong?
I fixed the picture according to the errors so far. I also forgot to add a wire from 13 to ground. I redid the switch to.

hgmjr

Joined Jan 28, 2005
9,027
It appears to me that the potentiometer is not hooked up the way it is drawn in the schematic you have posted. I think the green wire should be plugged into the same vertical row of holes now occupied by the red wire (connected to what I am guessing is the wiper terminal of the pot) and the brown wire that terminates in the clip. That way it works as a variable resistor which is what is called for in the schematic.

Actually is it tough to ascertain how the pot should be wire since the way it is drawn gives no clue as to which of the terminals is the wiper of the potentiometer. Suffice it to say that the wiper should be tied to one of the end terminals of the potentiometer and in so doing you turn a three terminal device into a two terminal device that operates as a variable resistor.

I am affraid I may have succeeded in confusing you.

hgmjr

tybomb

Joined Jan 23, 2007
17
The pot in the diagram I drew is facing you. It's hard to tell from my picture but I drew another one below. This is what my pot looks like and I have it hooked up this way.

tybomb

Joined Jan 23, 2007
17

hgmjr

Joined Jan 28, 2005
9,027
I'd like to buy extra components for this thing since I only have one of each at the moment. The only store within walking distance is this one however.
I can't seem to find the exact same parts.
http://www.thesourcecc.com/estore/C...atalog=Online&category=Parts&pagenum=1&sort=1
Mainly these.

100K Linear Potentiometer
or TS555CN CMos Timer IC
Decade counter with 10 decoded outputs IC

Is there anything here I can substitute for these three things?
100K Linear Potentiometer (See PART NUMBER 2710092)
or TS555CN CMos Timer IC (See PART NUMBER 2761723)
Decade counter with 10 decoded outputs IC ( No luck with this one)

If you are not averse to ordering parts on line, I can recommend www.digikey.com .

I think they still require you to purchase a minimum of $25 dollars US so that may be a deal killer. The total cost of the parts you need in single piece quantity is under$10 US.

hgmjr