| Electronics > Beginners |
| i need a design Review |
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| tron9000:
--- Quote from: hsn93 on June 07, 2018, 12:38:37 pm --- --- Quote from: tron9000 on June 06, 2018, 12:39:55 pm ---The 24V plane, it necks down too much, I see what you're trying to do by keeping it away from other circuitry by going round the outside, and as a result your necking the plane down. This should really be avoided. let the plane flow round the pins of the solenoid connectors to allow the pins 24V/Vsupply pins to connect. It would be a good idea to move this plane to an outside layer. Some bulk capacitors in the areas you've highlighted won't hurt and would take the sting out of any transient from the solenoids turning on. --- End quote --- im not sure i got you .. this is how i improved the design, the 24v plane now have better looking the pins are connected inside the plane is that what you mean as the pad has heat relief and which has low width ? and that hole (2) i connect it to the shield plane which is connected to chassis .. thats right? --- End quote --- Spot on, that's much better. Make sure that the plane wide enough for the max current flowing in that plane. I use the Saturn PCB application to calculate this as a guide. If you need to make the thermal relief traces wider, you can tweak the rules or make a new rule just for those connectors (Design -> Rules) and decrease the expansion or increase the air gap, and increase conductor width. This way you still get thermal relief and increase current capacity. Remember: minimum trace width in these rules is your calculated trace width to carry the total current divided by number of trace in thermal relief. So long as the its just the USB housing connected to pad number 2, and the coupling resistor and capacitor, it should be ok. |
| hsn93:
thank you everybody: this is my update design: things that i need to change next design: - RS485 Isolation - maybe JST connectors - LMZ to use lower power module - to remove power mux and cut usb power. - polyfuse or current protection for sensors. important things i should care of: - importance of leds - importance of silkscreen text - screw holes and heads - reduce component BOM is important - use same footprint as much as possible (for feature assembly) - use one layer on component when i've space (reduce stencil cut) - to care of necking power nets .. - placing pcb name, version ( i added after this post ) now im going to send this to PCB fabrication i will need to generate gerber files thank you everybody .. |
| dmills:
ULN2 pin 9 needs to be connected to the 24V line to make the internal flyback diodes work, which I am thinking you probably want. Regards, Dan. |
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