nuetron 64 Posted August 11, 2011 Share Posted August 11, 2011 Hi all, I came up with a schematic for a motor controller that will use four inputs to control two motors. Here is the simulation of one controller: http://www.falstad.com/circuit/#%24+1+5.0E-6+7.010541234668786+61+7.0+50%0Aw+416+256+432+256+0%0Aw+512+256+496+256+0%0Aw+416+288+432+304+0%0Aw+416+320+432+304+0%0Aw+512+288+496+304+0%0Aw+496+304+512+320+0%0Aw+416+352+432+352+0%0Aw+512+352+496+352+0%0AR+464+224+464+208+0+0+40.0+12.0+0.0+0.0+0.5%0Ad+464+224+464+256+1+0.805904783%0Ad+432+304+432+256+1+0.805904783%0Ad+432+352+432+304+1+0.805904783%0Ad+496+352+496+304+1+0.805904783%0Ad+496+304+496+256+1+0.805904783%0Ag+464+352+464+384+0%0Ar+544+272+592+272+0+5000.0%0Ar+544+336+592+336+0+5000.0%0Ar+384+272+336+272+0+5000.0%0Ar+384+336+336+336+0+5000.0%0Aw+336+272+336+224+0%0Aw+592+272+592+224+0%0Aw+592+224+528+224+0%0Aw+336+224+400+224+0%0AI+416+144+512+144+0+0.5%0Aw+384+144+384+112+0%0Aw+384+112+544+112+0%0Aw+544+112+544+144+0%0Al+448+304+480+304+0+0.1+0.08343826293630349%0At+544+272+512+272+0+1+-11.25643518222181+-0.18314397588528888+100.0%0At+544+336+512+336+0+1+0.5033703593065104+0.6865143354417993+100.0%0At+384+272+416+272+0+1+-10.387042258278903+0.6862489480575225+100.0%0At+384+336+416+336+0+1+-0.18314397588554787+2.4983541001169474E-10+100.0%0Aw+288+144+288+96+0%0Aw+288+96+416+96+0%0Aw+608+336+592+336+0%0Aw+336+336+320+336+0%0Aw+624+272+624+224+0%0Aw+304+224+304+272+0%0AI+384+144+320+144+0+0.5%0A151+304+144+304+224+0+2+5.0%0A151+624+144+624+224+0+2+5.0%0AI+544+144+608+144+0+0.5%0Aw+512+96+640+96+0%0Aw+640+96+640+144+0%0A150+528+144+528+224+0+2+0.0%0A150+400+144+400+224+0+2+5.0%0A154+608+272+608+336+0+2+5.0%0A154+320+272+320+336+0+2+0.0%0Ax+40+390+159+396+0+24+HH+%3D+Right%0Ax+39+362+137+368+0+24+HL+%3D+Left%0Ax+39+337+209+343+0+24+LH+%3D+Freewheel%0Ax+39+313+155+319+0+24+LL+%3D+Brake%0AL+384+112+384+48+0+1+false+5.0+0.0%0AL+416+96+416+48+0+1+false+5.0+0.0%0Aw+416+96+416+144+0%0Aw+512+96+416+96+0%0Aw+480+304+496+304+0%0Aw+448+304+432+304+0%0Aw+496+352+480+352+0%0Aw+480+352+464+352+0%0Aw+464+352+448+352+0%0Aw+448+352+432+352+0%0Aw+432+256+448+256+0%0Aw+448+256+464+256+0%0Aw+464+256+480+256+0%0Aw+480+256+496+256+0%0Ac+448+304+448+352+0+1.0E-5+0.18314397613538327%0Ac+480+304+480+352+0+1.0E-5+0.18314397613528888%0Ao+9+16+0+35+1.25+0.1+0+-1%0Ao+27+16+0+35+7.62939453125E-5+0.1+1+-1%0A And here is the schematic: I would like to get a few of these manufactured to sell, and thought I should run it by y'all first. Plus, I don't know where to place the components on the board, and I've never had anything manufactured before. :think: So, help please? EDIT: Will provide eagle .sch for whomever requests it. Quote Link to post Share on other sites
oPossum 1,083 Posted August 11, 2011 Share Posted August 11, 2011 Build a prototype of at least one H bridge on a breadboard or protoboard before you commit to having a PCB made. You will probably want to use a PNP transistor on the high side of the H bridge. Building and testing a prototype will make it very clear why. nuetron 1 Quote Link to post Share on other sites
RobG 1,892 Posted August 11, 2011 Share Posted August 11, 2011 ...You will probably want to use a PNP transistor on the high side of the H bridge... Even better, use MOSFETs. When using PNPs, you have to be careful what your Vdd is. If for example Vcc is 5V and Vdd 12V, then your PNP will always be on because logic gate's output will be 5V but it should be around 12V. You could use OC gates and pull-up to Vdd resistors. Quote Link to post Share on other sites
oPossum 1,083 Posted August 11, 2011 Share Posted August 11, 2011 Something to think about... nuetron and RobG 2 Quote Link to post Share on other sites
RobG 1,892 Posted August 11, 2011 Share Posted August 11, 2011 What if you used 7409 instead of 7408, that way you would not need Q2 and Q5. Quote Link to post Share on other sites
oPossum 1,083 Posted August 11, 2011 Share Posted August 11, 2011 Check the specs for max output voltage. It is typically 6 to 7 volts. 7401, 7403, 7438, etc.. NAND would be the type of gate needed. Quote Link to post Share on other sites
nuetron 64 Posted August 11, 2011 Author Share Posted August 11, 2011 Is there an open-collector version of the 4011? Quote Link to post Share on other sites
RobG 1,892 Posted August 11, 2011 Share Posted August 11, 2011 You mean open drain? Quote Link to post Share on other sites
nuetron 64 Posted August 11, 2011 Author Share Posted August 11, 2011 Sorry, yes. Quote Link to post Share on other sites
oPossum 1,083 Posted August 11, 2011 Share Posted August 11, 2011 40107 dual 2 input NAND open drain The spec sheet is unclear if the outputs can tolerate voltage above the supply. TI ST Quote Link to post Share on other sites
RobG 1,892 Posted August 11, 2011 Share Posted August 11, 2011 Check the specs for max output voltage. It is typically 6 to 7 volts. good point, there is a 15v NAND and some 30v buffers/inverters, but looks like transistor will be simpler. Quote Link to post Share on other sites
oPossum 1,083 Posted August 11, 2011 Share Posted August 11, 2011 15v NAND? what one? I missed it. Quote Link to post Share on other sites
nuetron 64 Posted August 11, 2011 Author Share Posted August 11, 2011 Hmm... Line driver... How about this? SN75452.PDF I have one of these on hand, I'll have to find out how much they cost. EDIT: $0.80 for one on digikey. Quote Link to post Share on other sites
RobG 1,892 Posted August 11, 2011 Share Posted August 11, 2011 15v NAND? what one? I missed it. 7426 Quote Link to post Share on other sites
nuetron 64 Posted August 11, 2011 Author Share Posted August 11, 2011 Here's the simulated version of oPossum's schematic. I'm going to test this, once I find my transistors... Quote Link to post Share on other sites
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