I suspect that without the free-wheeling diode the STAMP is getting whacked, because it Runs for the on-time that you've programmed and when it goes off (when you need the diode most) is when·it all goes flop-pot.·
If you look, the regulator isn't supplying power to the motor, thats coming direct from the SLA battery. I just had an idea! The regulator on the HWB is designed to drop 9V down to 5V, since I'm using a 12V battery instead of a 9V one, the reulator is doing 66% more work than it was designed to do. Could this be the cause of the thermal shutdown? Gadgetman, you said I could use a seperate batterys, one to power the HWB, the other for the motors; but that they need a common ground. How do I make two sepperate batteries have the same ground? Oh, PJ Allen, somehow, all my LEDs were broken.
crgwbr said...
If you look, the regulator isn't supplying power to the motor, thats coming direct from the SLA battery.
OK, I know, but, well, I'd mentioned the on-board regulator as someone brought it up; it's a big difference between the HomeWork Board and the B-o-E: the B-o-E has a regulator capable of supplying current/power for external circuitry. If the HomeWork Board IS crow-barring, it's because it's being asked to do too much or something undesirable is happening to it (e.g. taking a spike from a collapsing field.) 'Nuff said.
crgwbr
If you want to make them have a common ground they just hook a wire from the radioshack boards negative rail to the Vss of the WAM board then use a 9v battery to power your stamp or buy a 7805 regulator and wire it up to provide 5vdc to your WAM board from the power rails on your radioshack board tehn use the 12v to power your mosfet and motor. Also if it runs for a few seconds then resets this could be from noise you really need the diode on the motor radioshack has 1n4001 diodes for like a dollar for a few of them. If you use the 7805 to provide the power to your board then put a diode on the incomming power to the 7805.
I just finished the circuit that Beau posted, it is working, but not very good. When using an LED & Resister, LED gets bright and then dim then bright again; it should be on then off then on again. This probable means I need a schimitt trigger, right? The bad news is that once I swap out the LED for a motor, it goes back to not working; it'll run for a few seconds, then the stamp will turn off, and the motor keeps running. Electrical noise?
you should only need one diode for each motor. Are you tieing the vss of the WAM board to the grd of your protoboard then using a 9v battery to power your WAM board? Is your battery fully charged? Also make sure you have the diode connected correctly because if it was backwards it would make the motor run all the time. Are you using the 220 ohm resistor now?Also you can instal a 10k resistor from ground to the gate of the mosfet to help turn it off faster.·How about another picture of how you have it wired now.
Post Edited (bennettdan) : 6/10/2006 12:43:22 AM GMT
Hi,
Sorry, about the wait, I was on a trip, with no access to a computer.· Anyway, somebody said that the BOE would work better than the HWB, right?· If so, I'm gonna order a BOE tomarrow; I'm tiard of the HWB.
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NerdMaster
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The HomeWork board has a buck-regulator and it's, y'know, not intended for providing peripheral power as such (much as the one on a BS2.)
If you are ordering parts (diodes), get 1N4007... and maybe more of those FETs.
Post Edit --·For grins & giggles, you might want to try substituting an LED and resistor for the motor, just to see if the FET really IS working.
Post Edited (PJ Allen) : 6/8/2006 9:25:53 PM GMT
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NerdMaster
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If the HomeWork Board IS crow-barring, it's because it's being asked to do too much or something undesirable is happening to it (e.g. taking a spike from a collapsing field.)
'Nuff said.
If you want to make them have a common ground they just hook a wire from the radioshack boards negative rail to the Vss of the WAM board then use a 9v battery to power your stamp or buy a 7805 regulator and wire it up to provide 5vdc to your WAM board from the power rails on your radioshack board tehn use the 12v to power your mosfet and motor. Also if it runs for a few seconds then resets this could be from noise you really need the diode on the motor radioshack has 1n4001 diodes for like a dollar for a few of them. If you use the 7805 to provide the power to your board then put a diode on the incomming power to the 7805.
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Post Edited (bennettdan) : 6/10/2006 12:43:22 AM GMT
Sorry, about the wait, I was on a trip, with no access to a computer.· Anyway, somebody said that the BOE would work better than the HWB, right?· If so, I'm gonna order a BOE tomarrow; I'm tiard of the HWB.
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