the arrow symbol - novice question

[dennisr48]

Building my first project. I'm a total novice. After reading several books, I seem to be getting a handle on reading schematics. Only one symbol has me confused at this point. It's simply an arrow coming off the IC. Some guides indicate this is a male connector but no clue how to connect it? Another book suggests this could be a short-hand for connecting to + rail? Any help would be most appreciated.

 

[ericgibbs]

Building my first project. I'm a total novice. After reading several books, I seem to be getting a handle on reading schematics. Only one symbol has me confused at this point. It's simply an arrow coming off the IC. Some guides indicate this is a male connector but no clue how to connect it? Another book suggests this could be a short-hand for connecting to + rail? Any help would be most appreciated.

hi,
Without seeing the rest of the circuit diagram in context, its difficult to say.

Can you post the full circuit.?

 

[dennisr48]

Here's the full schematic

Many thanks for taking a look.

It's an optical audio device.

 

[blueroomelectronics]

It's a badly drawn schematic but it appears the arrow is the wiper of R2 (a 3 pin pot)

 

[dennisr48]

Many thanks Bill!

 

[ericgibbs]

Many thanks Bill!

What text book is that circuit from, its dreadful.?

As Bill states its the wiper of that pot R2.

 

[dennisr48]

Book title

It was from Electronic Sensors for the Evil Genius by Tom Petruzzellis. It's the least complicated project so I thought it would be good for a beginner such as myself. I hope the other schematics aren't as bad.

 

[Thunderchild]

It's a badly drawn schematic but it appears the arrow is the wiper of R2 (a 3 pin pot)

I would agree because otherwise the higher opamp would serve no pupose at all and I'm still trying to figure out what the whole thing is supposed to represent, I'm wondering if it will serve the intended pupose !

 

[Thunderchild]

It was from Electronic Sensors for the Evil Genius by Tom Petruzzellis. It's the least complicated project so I thought it would be good for a beginner such as myself. I hope the other schematics aren't as bad.

I suggest you return the book if possible thats the craziest diagram i have ever seen the sensor is in paralele with the power supply and serves no pupose at all, there shouldn't be a condenser on the putput of the top opamp as its outputting DC, the second opamp presumably is an amplifier ? or hoped to magically turn into and oscilator ? this too will probably do nothing as it has no gain set and so with a gain of 10'000 will just go into saturation the moment it gets power. all in all this is what i would expect a 10 year old to produce to find it in a text book is just plain barmy

 

[dennisr48]

Once again, I'm very grateful for your insight. You're a very helpful group. I suppose I should have known something was wrong when there was an item on the parts list that is not shown on the schematic. This circuit is intended to convert light into sound so that you can hear the differences between different types of light sources. I was just looking for a simple project to get my feet wet. I'm so glad you warned me about this shoddy book. I probably would have given up in frustration. I'll try another source to find some beginner projects.

 

[Mikebits]

Tom Petruzzellis use to be an editor for popular electronics.

 

[Mikebits]

I may be wrong, but I think the circuit is missing a resistor from the sensor diodes cathode to Vbatt +. (See attached).

I am thinking U2 is a comparator, and when you pulse the photodiode with something like a IR remote that the output to the speaker will be squarewaves. May be better to just strobe an LED.

Also, the sensor seems to be running in the reverse mode, which may not be best. See section 3 of this app note.
https://www.electro-tech-online.com/custompdfs/2008/12/photodiode_technical_information.pdf

 

[picbits]

That is one awful schematic

 

[Thunderchild]

what I don't get is how can there be so much garbage out there in the way of books, I bought 2 PIC books both of which were utter rubbish one of them the auther clearly just wanted to make money as it was large print rambled on about off topic things and then was full of a load of very complicated and poorly documented projects taken from microchip it was bassically robbery I'm not pleased at all at the prospect of buying yet more electronics/pic books that are purely money makers for the authors it seems that this sort of dishonesty is perfectly acceptable in our society, if I had my way the authors of such garbage should be held responsable for their trash and have to personally refund money wasted on such books