Originally posted by NewGuy+May 13 2006, 06:07 PM--><div class='quotetop'>QUOTE(NewGuy @ May 13 2006, 06:07 PM)</div><div class='quotemain'> (O/P, Mofet Switch, Comparator, Voltage Divider) These are electrical components I've never heard of.

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[/b]

"o/p" = "output"

"mosfet" = metal oxide semiconductor field effect transistor = the thing in Ron's schematic labled "M1" - we're using it as a solid state switch in this application.

"comparator" = an op amp (operational amplifier) configured to compare a voltage input with a reference inptu - Ron has chosen half of an LM393 (a common integrated circuit op amp, two to a chip) and labled it "U1a" in his schematic.

R3 and R6 form a "voltage divider" which sets the reference voltage. It divides the applied voltage by the ratio of the two resistances. R5 is your pressure sensor, which forms another voltage divider with R8 and R2, thereby developing a voltage proportional to the pressure applied.

R8 allows for adjustment to compensate for variation between individual sensors - it is a "variable resistor" or "potentiameter." It is the "trim pot" I spoke of. "Trim" means "adjusted by creator or manitainer rather than by operator."

Originally posted by NewGuy@May 13 2006, 06:07 PM
This item called a Trim Pot; if one is used, can it be used as a type of manual adjustment by the end user of this little electrical gizmo to adjust the sensitivity of the force sensor to a specific force bewteen 0 to 100 pounds?

[post=17063]Quoted post[/post]​

A trim pot is not a typically a user adjustment, but a more user convenient pot could be used instead. This would require the doofarb to be calibrated by the user.

Originally posted by NewGuy@May 13 2006, 06:07 PM
Just for the sake of argument, lets say we used all or most of the electrical components you've just listed. How much space will a circuit consisting of such components take up? Can they be assembled in a "Micro-Circuitry" type of configuration?

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With the batteries on a separate board, using SMT (surface mount technology) components and a bit of fussing around - maybee 1" x 1.25" x 1/2". Without the SMT, which would be easier to build, maybee 5% or 10% bigger. (Would need a different MOSFET if you go without SMT. No big problem.)

Originally posted by NewGuy@May 13 2006, 06:07 PM
What would be a ball park price of the individual components you've listed?

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Depends on where one shops. With all new components from a reputable supply house, maybee ten or twenty bucks. From Radio Schmuck, maybee twice that. With surplus parts and some digging around online, maybee five or ten bucks. SMT parts are a little harder to find through surplus.

Originally posted by NewGuy@May 13 2006, 06:07 PM
Can you recommend a website with some kind of Electronics Glossary where I might be able to look up the meanings and applications of some of the components you mentioned? I'd like to be just a little bit smarter the next time I log onto this site if I can.

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Can I ever!! Scroll up to the top of this page. Look for the smaller "All About Circuits" under the larger identical phrase. Click on it! Enjoy!

<!--QuoteBegin-NewGuy@May 13 2006, 06:07 PM

"Dios te lo paga."

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[/quote]
De nada, hombre, de nada. Besides, Ron H did all the work...

 

double posted...

 

Originally posted by thingmaker3@May 14 2006, 03:10 PM
If "resistance is futile" - would resistance in parallel be even more futile?

LOL! Actually, though, wouldn't resistance in series be even more futile?

resistance=futile
2*resistance=2*futile

 

Originally posted by Ron H@May 14 2006, 06:08 PM
LOL! Actually, though, wouldn't resistance in series be even more futile?

resistance=futile
2*resistance=2*futile

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Hi Ron.

I just wanted to thank you for the Schematic/Electronic Hiragliph. I've been told by two different people that this is most likely what I've been looking for in my quest for the right circuit.
I also wanted to ask you about something called a "DoorFarb and where it would be placed within the schematic that you've drawn up? My reason for asking is because I posed a question to thingmaker3 regarding a "Trim Pot." I wondered if the end-user of my little electrical gizmo could use the "Trim Pot" as a means of adjusting the sensitivity of my sensor/switch for themselves. This would allow them to adjust to the specific pound weight sensitivity they desired.
He mentioned the "DoorFarb" as a possible solution.
Such a component would be for another time and another upgrade of this same little gizmo but, it sounded intriguing so, I thought I'd ask. For now, I have enough information to move forward with my present upgrade of this ongoing project.
First things first though; I have to learn how to inturpret this Schematic for myself. Then I can move on to learning about the individual components and how they work.
I've started reading the "All About Circuits" book that this website has available. I haven't gotten very far yet but, already the things that yourself and others have put forth seem to make just a little more sense. It's going to be a long process because reading puts me right to sleep.
Most of the practical things I've ever learned were learned by hands-on kind of training. It's a peculiar thing but, I can read a tutorial out of a book or whatever and bearly remember what I just read. On the other hand, if I have my computer read that same tutorial to me out loud, I can retain so much more of that information.
Any how; I'm off to school to learn how to read these Electronic Hyrogliphs. I'll check back again later. If I run into some information that I don't understand, perhaps you or one of the other good guys in this forum site can steer me in the right direction.
Thanks again Ron; and thingmaker3; and Spoggles; and a couple of others whose usernames don't appear on this page any more.

 

Who mentioned "doorfarb"? I think someone is pulling your chain. I'm pretty sure you can get a doorfarb at the skyhook store, right next to the lefthanded monkeywrenches, which are next to the muffler bearings.
You can use the trimpot to adjust the threshold (sensitivity). You could use a real potentiometer, complete with knob, if you have room for it.

 

I apologise for my ambiguity. "Doofarb" is a local colloqualism, similar to "thingamabob" or "gizmo." I was refering to the end-packaged device as a whole. (Some kind of sporting equipment or something?) If it includes a knob that will alter the activation pressure, then the end-user will have to do a bit of calibrating.

 

Originally posted by thingmaker3@May 16 2006, 05:51 AM
I apologise for my ambiguity. "Doofarb" is a local colloqualism, similar to "thingamabob" or "gizmo." I was refering to the end-packaged device as a whole. (Some kind of sporting equipment or something?) If it includes a knob that will alter the activation pressure, then the end-user will have to do a bit of calibrating.

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Ah, a doohickey.
No wonder Google couldn't find it, though. NewGuy had added an extra "r". Shame, NewGuy!

 

Originally posted by Ron H@May 16 2006, 05:14 AM
Ah, a doohickey.
No wonder Google couldn't find it, though. NewGuy had added an extra "r". Shame, NewGuy!

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DooFarb, DooFarb; sorry about the misspelling. This is the perfect example of how much I know about electronics and electronic jargon. I bet you guys thought I was exaggerating when I said I was Electronically Challanged.
But still, I think that adding an additional doohickey that allows the end-user to adjust this little electrical gizmo for themselves is an excellent idea worthy of future examination.
With the doing away of my present mechanical ON/OFF switch I now have the luxury of a little more room for add-ons. I breath a sigh of relief because the Finding-A-Correct-Cicuit part of my quest seems to be behind me now.
It's on to the hard part now; learning how to put it all together. I've got the solder and the soldering gun ready.

Thank you gentleman.

 

Originally posted by NewGuy@May 16 2006, 05:02 PM
DooFarb, DooFarb; sorry about the misspelling. This is the perfect example of how much I know about electronics and electronic jargon. I bet you guys thought I was exaggerating when I said I was Electronically Challanged.
But still, I think that adding an additional doohickey that allows the end-user to adjust this little electrical gizmo for themselves is an excellent idea worthy of future examination.
With the doing away of my present mechanical ON/OFF switch I now have the luxury of a little more room for add-ons. I breath a sigh of relief because the Finding-A-Correct-Cicuit part of my quest seems to be behind me now.
It's on to the hard part now; learning how to put it all together. I've got the solder and the soldering gun ready.

Thank you gentleman.

[post=17163]Quoted post[/post]​

A small, fine-tipped soldering iron (25-30 watts) would be better.

 

Have a look at this, especially chapters two and three:
NEETS Module

The whole NEETS series is an adequate electronics reference.

 

Originally posted by thingmaker3@May 17 2006, 02:49 AM
Have a look at this, especially chapters two and three:
NEETS Module

The whole NEETS series is an adequate electronics reference.

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Greeting thingmaker3:

I'm in the process of gathering all the components for my first assembly attempt of the schematic that Ron H. drew up for me.
I have a question regarding a couple of the components before I fire up the soldering gun. (so to speak) FNG311n and the LM393--These little doodads have lots of little legs attatched to them.
I believe one of them has six little legs and the other has 8 legs.
Do all the little legs on these components have to connect to something? In Ron's schematic, it only shows them as being a part of the over all schematic. I suppose that it was assumed that who ever read this schematic also must have enough knowhow to know how to connect all the legs on these two components. I'm pretty sure that normally that would be the case however, I'm not your typical electronics person.
All the other little components have only an input end and an output end so, (+/-) I'm OK with those. It's just the two components I've listed above that are giving me fits. Can you recommend a source for some more information on these doodads? I've checked the techinical specs for each of these components hoping to find a clue as to how to connect them but, all I really got was graphs and numbers and pictures of these parts along with internal schematics for each of these components.
Ron H. If you read this, I meant to ask you since you're the one that drew up the schematic but, I wasn't sure of the protocal on this forum. I didn't know if I had to add my replies to the last entry in this string or if I could have gone back to the the post that included your schematic. I elected to just add to the last reply; which was from thingmaker3.
Thanks in advance for any input you can share. Hope to hear from you soon.

 

Originally posted by NewGuy@May 20 2006, 03:53 PM
Greeting thingmaker3:

I'm in the process of gathering all the components for my first assembly attempt of the schematic that Ron H. drew up for me.
I have a question regarding a couple of the components before I fire up the soldering gun. (so to speak) FNG311n and the LM393--These little doodads have lots of little legs attatched to them.
I believe one of them has six little legs and the other has 8 legs.
Do all the little legs on these components have to connect to something? In Ron's schematic, it only shows them as being a part of the over all schematic. I suppose that it was assumed that who ever read this schematic also must have enough knowhow to know how to connect all the legs on these two components. I'm pretty sure that normally that would be the case however, I'm not your typical electronics person.
All the other little components have only an input end and an output end so, (+/-) I'm OK with those. It's just the two components I've listed above that are giving me fits. Can you recommend a source for some more information on these doodads? I've checked the techinical specs for each of these components hoping to find a clue as to how to connect them but, all I really got was graphs and numbers and pictures of these parts along with internal schematics for each of these components.
Ron H. If you read this, I meant to ask you since you're the one that drew up the schematic but, I wasn't sure of the protocal on this forum. I didn't know if I had to add my replies to the last entry in this string or if I could have gone back to the the post that included your schematic. I elected to just add to the last reply; which was from thingmaker3.
Thanks in advance for any input you can share. Hope to hear from you soon.

[post=17249]Quoted post[/post]​

Hi, NewGuy,
You can quote any message in the thread and then reply to it.
For the LM393, I showed explicitly the connections for each pin. "NC" means No Connection.
For the FDG311N, I showed S, D, and G. See the attached drawing, which is from the SDG311N datasheet. Connect pins 1, 2, 5, and 6 to your gizmo. Connect pin 4 to the node that connects to the negative terminal of the battery. Connect pin 3 to pin 1 on the LM393.

 

Originally posted by Ron H@May 20 2006, 06:50 PM
Hi, NewGuy,
You can quote any message in the thread and then reply to it.
For the LM393, I showed explicitly the connections for each pin. "NC" means No Connection.
For the FDG311N, I showed S, D, and G. See the attached drawing, which is from the SDG311N datasheet. Connect pins 1, 2, 5, and 6 to your gizmo. Connect pin 4 to the node that connects to the negative terminal of the battery. Connect pin 3 to pin 1 on the LM393.

[post=17251]Quoted post[/post]​

Hi Ron H.
Thanks very much for the quick reply. I'm getting there slowly but, surely. Once I've gathered up all the components, I intend to lay them out on my work bench in the order they're in on the schematic and just stare at them for a while.
On a small set up like this, can you tell me what kind of backing I should use to anchor all this stuff together? Do they make some kind of readily available pre-fab circuit board for small projects like this?
I see now, after you've explained it to me, that you did in fact explicitly show the connection for each pin. After reading your relpy I'm afraid perhaps I've tested the limits of your patience regarding this circuit. That wasn't my intention.
Although I now know a little bit more about this type of circuitry now than I did when I first started this string of questions, I still don't know quite enough to completely figure them out for myself; even when the answers are staring me right in the face.

Thanks for your help Ron; and for your patience.

 

Originally posted by Ron H@May 20 2006, 06:50 PM
Hi, NewGuy,
You can quote any message in the thread and then reply to it.
For the LM393, I showed explicitly the connections for each pin. "NC" means No Connection.
For the FDG311N, I showed S, D, and G. See the attached drawing, which is from the SDG311N datasheet. Connect pins 1, 2, 5, and 6 to your gizmo. Connect pin 4 to the node that connects to the negative terminal of the battery. Connect pin 3 to pin 1 on the LM393.

[post=17251]Quoted post[/post]​

Hi Ron H.
Thanks very much for the quick reply. I'm getting there slowly but, surely. Once I've gathered up all the components, I intend to lay them out on my work bench in the order they're in on the schematic and just stare at them for a while.
On a small set up like this, can you tell me what kind of backing I should use to anchor all this stuff together? Do they make some kind of readily available pre-fab circuit board for small projects like this?
I see now, after you've explained it to me, that you did in fact explicitly show the connection for each pin. After reading your relpy I'm afraid perhaps I've tested the limits of your patience regarding this circuit. That wasn't my intention.
Although I now know a little bit more about this type of circuitry now than I did when I first started this string of questions, I still don't know quite enough to completely figure them out for myself; even when the answers are staring me right in the face.

Thanks for your help Ron; and for your patience.

 

Originally posted by NewGuy@May 21 2006, 04:50 PM
Hi Ron H.
Thanks very much for the quick reply.  I'm getting there slowly but, surely.  Once I've gathered up all the components, I intend to lay them out on my work bench in the order they're in on the schematic and just stare at them for a while. 
On a small set up like this, can you tell me what kind of backing I should use to anchor all this stuff together?  Do they make some kind of readily available pre-fab circuit board for small projects like this?
I see now, after you've explained it to me, that you did in fact explicitly show the connection for each pin. After reading your relpy I'm afraid perhaps I've tested the limits of your patience regarding this circuit.  That wasn't my intention.
Although I now know a little bit more about this type of circuitry now than I did when I first started this string of questions,  I still don't know quite enough to completely figure them out for myself; even when the answers are staring me right in the face.

Thanks for your help Ron; and for your patience.

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I am sometimes short and to the point. I'm sorry if I sounded impatient. I understand where you are coming from. I really appreciate the fact that you can put your thoughts into print coherently. Poor spelling and grammar are the things that really try my patience.
I build breadboards from material that I buy prefabbed. It has plated-through holes on 0.1 inch centers, and a "ground plane" on one side (copper in the spaces between the holes, but isolated from them). In this case, I would use this ground plane as the node that connects to the negative side of your battery. In fact, I had to restrain myself from adding a ground (GND) symbol to that node in the schematic, because it would almost certainly just add to your confusion.
You might have trouble finding a small piece of this material. I buy sheets that are about 10 inches by 17 inches, and the last one I bought, several years ago, cost about US $120. I cut it into small pieces for my little projects. You might be able to find similar material with or without the GND plane in smaller pieces. For your project, you probably don't need the plane, but keep the wires highlighted in red below as short as possible.

 

Hi Ron H.

I got both of your most recent replies. Thanks alot for the heads-up on the "Short Wires" schematic.
I seem to recall reading somewhere about the length and gage of certain circuit wires affecting the amount of current running through them. Is that the reason for making the Red outlined wires in this schematic short or is it just a space/time/money saving measure?
I've been looking through a long list of available pre-made circuit boards on the Ebay website. It seems to be a good place for me to pick up smaller pieces of the type of circuit board you mentioned.
Can this type of circuit board be cut to odd-ball shapes or are they strictly rectangular grids made to be used as rectangular circuit layouts? Just curious.
This weekend I'll be milling the parts for my last Prototype Gizmo with the mechanical On/Off switch. I look forward to seeing just how much space I'll have available now that I'll be moving to an all Electronic Gizmo.
Ron, do you remember the first little Gizmo that you ever dreamed up and put together that actually worked as intended?
If all goes according to plan, this will make two in a row for me. The second in this "Row" being the upgraded version of this same Little Gizmo. This time around I can't take all of the credit but, it's still gratifying.
This is perhaps an inappropriate analogy but, It's kind of like having a Wet-Dream two nights in a row and enjoying the second night a little more than the first.
In one of my previous replies I ignorantly inquired about something called a "DooFarb." This "DooFarb" was mentioned by thingmaker3 in a reply to my inquiry about possibly setting up my Little Gizmo with an electronic means of adjustment by the End User of this item.
Do you think such a thing is possible given the space requirements I listed early on in this forum?

Ron, many thanks for your continued replies. Hope to hear from you again.

 

I got both of your most recent replies. Thanks alot for the heads-up on the "Short Wires" schematic.
I seem to recall reading somewhere about the length and gage of certain circuit wires affecting the amount of current running through them. Is that the reason for making the Red outlined wires in this schematic short or is it just a space/time/money saving measure?
Short wires minimize impedance so that your gizmo sees a solid power supply voltage. Otherwise, current transients in your gizmo can cause the power supply voltages to "bounce", which may or may not be a problem, since I don't know what your gizmo does.
I've been looking through a long list of available pre-made circuit boards on the Ebay website. It seems to be a good place for me to pick up smaller pieces of the type of circuit board you mentioned.
Can this type of circuit board be cut to odd-ball shapes or are they strictly rectangular grids made to be used as rectangular circuit layouts? Just curious.
The stuff I have has a rectangular array of holes, but that doesn't preclude cutting it to be shaped like a butterfly.
This weekend I'll be milling the parts for my last Prototype Gizmo with the mechanical On/Off switch. I look forward to seeing just how much space I'll have available now that I'll be moving to an all Electronic Gizmo.
Ron, do you remember the first little Gizmo that you ever dreamed up and put together that actually worked as intended?
If all goes according to plan, this will make two in a row for me. The second in this "Row" being the upgraded version of this same Little Gizmo. This time around I can't take all of the credit but, it's still gratifying.
This is perhaps an inappropriate analogy but, It's kind of like having a Wet-Dream two nights in a row and enjoying the second night a little more than the first.
In one of my previous replies I ignorantly inquired about something called a "DooFarb." This "DooFarb" was mentioned by thingmaker3 in a reply to my inquiry about possibly setting up my Little Gizmo with an electronic means of adjustment by the End User of this item.
Do you think such a thing is possible given the space requirements I listed early on in this forum?
You'll have to figure that out for yourself. R2 is the adjustment. Search vendors like Mouser for potentiometers. If you need a shaft and a knob, it will require more room. If you can get by with a miniature pot, which can be tweaked with a trimming tool (like a small screwdriver, only nonmetallic), it can be pretty small.

Ron, many thanks for your continued replies. Hope to hear from you again.

My replies are in red. BTW, if you are going to sell this, I deserve a cut.

 

The whole NEETS series can be found at Davidson College in pdf format.

 

Nice find, Joe!! Thanks for the link. My hard copies are not in the condition they were twenty years ago. (Then again, neither am I. )

 

double post. drat.