konradIC13
Member
Hello,
Is my another thread, its the final one My project has evolved to its almost final stage. I present a complete (maybe?) schematic of it.
What it will do?
- AVR controlled cooling pad
- Depending from input signal (from switches SW[1,2,3] ATmega8 with use of logic function will turn on/off appropriate fans and segments of RGB Led (common anode), the action will be either to turn on or off just 1 and 0.
- situation where only 1 RGB LED segment is on and only 1 fan works might happen but also there might be situation where the whole RGB diode is on and all fans are on
Parameters of fans, LED:
- FAN1 takes 240mA of current, FAN2 takes also 240mA of current
- FAN3 takes 220mA of current
- FAN4 takes 200mA of current
- RGB LED is common anode, the If of each segment (for Red, for Green, for Blue) is 20mA, voltage drop is 1.95V for Red, 3.3V for Green and 3.3V for Blue
ATmega8 output electrical characteristics:
- output current max 20mA
- output voltage low max 0.9V, high min 4.5V
Other:
- Powered from 9V DC adapter, stabilized at 5V with 78S05 (max 2A)
Questions and thoughts:
- R2, R4, R6 resistor values, are they big enough to protect MOSFET gate?
- did i place all components related to good work of U1, U4 and U6 MOSFETs? are there any other transistors i should attach to them?
- did i place all components related to good work of Q1, Q2 and Q3 NPN transistor? are there any other transistors i should attach to them?
- voltage regulator capacitor values, good/bad should I change something?
- do i have to place current limiting resistors before fans? They are 5V DC brushless fans, 5V is rated voltage and with that voltage rated current drain are as i listed above
- is there anything else i should know/change in my schematic?
View attachment 65227
Is my another thread, its the final one My project has evolved to its almost final stage. I present a complete (maybe?) schematic of it.
What it will do?
- AVR controlled cooling pad
- Depending from input signal (from switches SW[1,2,3] ATmega8 with use of logic function will turn on/off appropriate fans and segments of RGB Led (common anode), the action will be either to turn on or off just 1 and 0.
- situation where only 1 RGB LED segment is on and only 1 fan works might happen but also there might be situation where the whole RGB diode is on and all fans are on
Parameters of fans, LED:
- FAN1 takes 240mA of current, FAN2 takes also 240mA of current
- FAN3 takes 220mA of current
- FAN4 takes 200mA of current
- RGB LED is common anode, the If of each segment (for Red, for Green, for Blue) is 20mA, voltage drop is 1.95V for Red, 3.3V for Green and 3.3V for Blue
ATmega8 output electrical characteristics:
- output current max 20mA
- output voltage low max 0.9V, high min 4.5V
Other:
- Powered from 9V DC adapter, stabilized at 5V with 78S05 (max 2A)
Questions and thoughts:
- R2, R4, R6 resistor values, are they big enough to protect MOSFET gate?
- did i place all components related to good work of U1, U4 and U6 MOSFETs? are there any other transistors i should attach to them?
- did i place all components related to good work of Q1, Q2 and Q3 NPN transistor? are there any other transistors i should attach to them?
- voltage regulator capacitor values, good/bad should I change something?
- do i have to place current limiting resistors before fans? They are 5V DC brushless fans, 5V is rated voltage and with that voltage rated current drain are as i listed above
- is there anything else i should know/change in my schematic?
View attachment 65227