konradIC13
Member
Hello,
The project I showed in my previous post have expanded a bit.
Im trying to upgrade my laptop cooling pad to something bigger. It will consist of 3 sets of fans (2 + 2 +1), RGB led indicator and 3 SPDT switches to contol fans.
There will be 4 modes of work:
- S1+S2
- S3+S4 S5
- S1+S2 S3+S4
- S1+S2 S3+S4 S5
Each state of work will be indicated by diffrend color from RGB Led:
- yellow R+G
- white R+G+B
- cyan G+B
- magenta R+B
Problems:
- powering circuit - the estimated current maximum current draw will be approx 1.5A (inlcuding fans, leds, CMOS IC and transistors)
Firstly i planned to power it directly from USB port but its impossible since USB gives max 500mA even if i would use multiple ports it would be uncomfortable.
Also i wanted to power it from LiPo 7.8v battery pack but there was another problem - voltage stabiliser, it would have to give 1.5A and it would have to be LDO stabiliser, i have found several on internet but they are not avaliable to buy in my country ( in quantities <100 ) and those LDO that are avaliable are expensive and have lower current rating.
Then an idea came to my mind. Is it possible to have 2 work modes? In one, when circuit is powered from USB port, the S1+S2 are working without any control but when you attach extra power (and the USB is cut off either automatically or you manually unplug it) the circuit is fully operational with 3 switch control + led and all the logic functions etc. The other power source would be propably 5V stabilised supply. It would be great but unfortunatly i cant think of anything that would let me make it work that way. Also
- schematic verification (the logic funcitons are 100% fine no need to check that) - i have already made some changes in schematic since i last published it here, all logic chips are connected and are preforming nessesary logic functions. The swithing transistors for fans are IRF3711 (again i tried to find something cheaper and more suited to my project that will be logic level mosfet but other are either more expensive or they are not avaliable ._.), the switching transistor that controls RGB LED are 2n2222 that are connected to each of diode katode (there is one anode and 3 katodes). The values of resistors, are they fine? Especially those that are responsible for good transistor work. Did i miss something?
The project I showed in my previous post have expanded a bit.
Im trying to upgrade my laptop cooling pad to something bigger. It will consist of 3 sets of fans (2 + 2 +1), RGB led indicator and 3 SPDT switches to contol fans.
There will be 4 modes of work:
- S1+S2
- S3+S4 S5
- S1+S2 S3+S4
- S1+S2 S3+S4 S5
Each state of work will be indicated by diffrend color from RGB Led:
- yellow R+G
- white R+G+B
- cyan G+B
- magenta R+B
Problems:
- powering circuit - the estimated current maximum current draw will be approx 1.5A (inlcuding fans, leds, CMOS IC and transistors)
Firstly i planned to power it directly from USB port but its impossible since USB gives max 500mA even if i would use multiple ports it would be uncomfortable.
Also i wanted to power it from LiPo 7.8v battery pack but there was another problem - voltage stabiliser, it would have to give 1.5A and it would have to be LDO stabiliser, i have found several on internet but they are not avaliable to buy in my country ( in quantities <100 ) and those LDO that are avaliable are expensive and have lower current rating.
Then an idea came to my mind. Is it possible to have 2 work modes? In one, when circuit is powered from USB port, the S1+S2 are working without any control but when you attach extra power (and the USB is cut off either automatically or you manually unplug it) the circuit is fully operational with 3 switch control + led and all the logic functions etc. The other power source would be propably 5V stabilised supply. It would be great but unfortunatly i cant think of anything that would let me make it work that way. Also
- schematic verification (the logic funcitons are 100% fine no need to check that) - i have already made some changes in schematic since i last published it here, all logic chips are connected and are preforming nessesary logic functions. The swithing transistors for fans are IRF3711 (again i tried to find something cheaper and more suited to my project that will be logic level mosfet but other are either more expensive or they are not avaliable ._.), the switching transistor that controls RGB LED are 2n2222 that are connected to each of diode katode (there is one anode and 3 katodes). The values of resistors, are they fine? Especially those that are responsible for good transistor work. Did i miss something?
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