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Topic: transistor switch logic . very hard to solve this scenario. (Read 4711 times) previous topic - next topic

HazardsMind

the darlington has no resistor in the base?
Quote

Nope, just follow the link I gave you, to wire it.
My GitHub:
https://github.com/AndrewMascolo?tab=repositories

jaylisto


the darlington has no resistor in the base?
Quote

Nope, just follow the link I gave you, to wire it.


i will try this thing.

i will also try the relay style of the others suggested solution
jaylisto

AWOL

Quote
You need to use two relays, one DPDT to determine forward/reverse and a one SPST to to perform the stop/go command, this second relay's contacts is simply wired in series with the positive voltage coming from the motor battery.

Or, if you want speed control and have an appropriate transistor, you use that in place of the single-pole relay, and just use the DPDT for reverse.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

jaylisto


Quote
You need to use two relays, one DPDT to determine forward/reverse and a one SPST to to perform the stop/go command, this second relay's contacts is simply wired in series with the positive voltage coming from the motor battery.

Or, if you want speed control and have an appropriate transistor, you use that in place of the single-pole relay, and just use the DPDT for reverse.


o! my friend will travel to manila, i will give her a favor to buy what i need.

some one say here that their is an hbrige built in an i.c? what exactly the name of the ic?

that has the capability of giving what i want. pls suggest what is that hbridge ic. to be sure do not suggest rare ones. thank you so much. im looking forward for your reply.
jaylisto

HazardsMind

My GitHub:
https://github.com/AndrewMascolo?tab=repositories

jaylisto


The two most common are SN754410 and L293D


what is the difference between the two?

i search it and sn754410 looks like it only uses 1 motor.

and l293d can handle 2 motors.

so what do you prefer? note: i only have 3v for trigger, and 7v for the higher voltage.
jaylisto

HazardsMind

The SN754410 can handle two motors @ 1Amp, the L293d I think can handle 2-3 Amps.
My GitHub:
https://github.com/AndrewMascolo?tab=repositories

jaylisto


The SN754410 can handle two motors @ 1Amp, the L293d I think can handle 2-3 Amps.


thank you very much. i think ill take l293d.
jaylisto

jaylisto


The SN754410 can handle two motors @ 1Amp, the L293d I think can handle 2-3 Amps.


now i have two L293D chip.

can some one gives me the diagram on it pls?

note, my battery is 6v 4ah sla battery.
jaylisto

AWOL

Doesn't one of the motor shields use the L293?
There should be a schematic over at the Main Site
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

jaylisto


Doesn't one of the motor shields use the L293?
There should be a schematic over at the Main Site


i dont know, i cant understand the diagrams i searched.

check out what ive done. can this thing work? since my hbridge is expensive and very hard to find availablitiy , i dont want to mess it up.


any corrections?.
jaylisto

HazardsMind

That's correct, but you can increase the actuall Vcc voltage to 5 - 12V. Keep the enable at 5V thou. That chip can also do PWM.
My GitHub:
https://github.com/AndrewMascolo?tab=repositories

AWOL

http://arduino.cc/en/uploads/Main/arduino_MotorShield_Rev3-schematic.pdf

You can ignore the current-sense amplifier.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

jaylisto



thanks for all help. the hbridge chip is now working.

this maybe an out of topic question. pls answer


i have a 12v battery source. the regulator is in parallel. the 7809 suppose to regulate 9v. and the 7805 is 5v.

when i test them. the 7809 output has only 6v and the other is only 3v. why did this happen?




do i need to get them in series?
jaylisto

HazardsMind

Not enought current maybe. If you take one of them off, does it output the correct voltage?
My GitHub:
https://github.com/AndrewMascolo?tab=repositories

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