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Topic: Please check my schematic. (Read 58 times) previous topic - next topic

mOskit

Apr 18, 2015, 01:44 pm Last Edit: Apr 18, 2015, 01:45 pm by mOskit
Can i ask someone to check my schematic please.
It`s an 12v-18v powered i2c  dc coil driver with 6 analog sensor with range 0.5v-4.5v.
i don`t know how to upload the actual eagle schematic i made, so picture is only what i could post.
Thanks for any help.

Bainesbunch

D1 to D8 why are you using zeners and not a simple 2n1400 for flyback ?

Why so many attiny85 and not something like a mega2560 or even a 328 with an analogue MUX for the inputs

it seem a bit of overkill for all those MCUs

Cheers Pete.
EmbeddedAT .. From Concept to Prototype to Production
Electronics and firmware design and project mentoring
I do answer personal requests for help when accompanied with a PayPal receipt ;)

LarryD

#2
Apr 18, 2015, 05:13 pm Last Edit: Apr 18, 2015, 05:14 pm by LarryD
I would add a ceramic .1uF at the pins 1-3 of the 7805 regular,
and move the diode to the left of the input capacitor.
The way you have it in your schematic isn't the same as how you have it wired up!

mOskit

D1 to D8 why are you using zeners and not a simple 2n1400 for flyback ?

Why so many attiny85 and not something like a mega2560 or even a 328 with an analogue MUX for the inputs

it seem a bit of overkill for all those MCUs

Cheers Pete.
diodes it`s my mistake, i`ll get it changed.
regarding all those tiny85`s, the reason for that is that i couldn`t manage to send 6 sensor data throught
i2c in one go. We was trying to put them in buffer with 328, but when it comes to drive outputs than that was just to much for me. simpler for me was to use hybrid with individual address(each bank 1 sensor 2 outputs) this way i can write code that i i think works as i want.

LarryD thanks for your suggenstion.

Bainesbunch

diodes it`s my mistake, i`ll get it changed.
regarding all those tiny85`s, the reason for that is that i couldn`t manage to send 6 sensor data throught
i2c in one go. We was trying to put them in buffer with 328, but when it comes to drive outputs than that was just to much for me. simpler for me was to use hybrid with individual address(each bank 1 sensor 2 outputs) this way i can write code that i i think works as i want.

LarryD thanks for your suggenstion.
OK NP Good luck with the project :) and have fun !!
EmbeddedAT .. From Concept to Prototype to Production
Electronics and firmware design and project mentoring
I do answer personal requests for help when accompanied with a PayPal receipt ;)

mOskit

Don`t you guys think i should use some caps with analog sensors??

MarkT

Why 10 ohm gate resistors?  The output resistance of the ATtiny's pins is about 40 ohms,
and you might want to limit the surge current anyway to the abs max ratings with 150 ohm
resistor or so.
[ I won't respond to messages, use the forum please ]

mOskit

MarkT the resistor was suggested in project guideiance. Should i replace with 150ohm?

Bainesbunch

Anything will do to limit the current draw on the pin to a bit below it maximum rating that also allows for the transistor to fire.
EmbeddedAT .. From Concept to Prototype to Production
Electronics and firmware design and project mentoring
I do answer personal requests for help when accompanied with a PayPal receipt ;)

CrossRoads

red & green on black - I find that very hard to read.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

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