Show Posts
Pages: [1] 2
1  Using Arduino / Motors, Mechanics, and Power / Re: H-bridge BJT problem on: January 28, 2014, 05:56:03 pm
Maybe less than 50% is not enough to get the motor started moving. What kind of load is on the motor?

none,,
2  Using Arduino / Motors, Mechanics, and Power / Re: H-bridge BJT problem on: January 28, 2014, 07:43:20 am
How are you driving this?

To turn in one direction, keep one Arduino output Low, and use PWM to turn the other one On.

To turn in the other direction, keep the other Arduino output Low, and use PWM on the first.

If you are PWMing both Arduino outputs, that could explain your problem. Maybe.

yup the other side is low and the motor is only moving when the PWM is >50%
3  Using Arduino / Motors, Mechanics, and Power / Re: H-bridge BJT problem on: January 27, 2014, 05:20:12 am
btw what is the best frequency for PWM i use 19.3KHz and the motor is only moving when the PWM duty cycle is >50%.
4  Using Arduino / Motors, Mechanics, and Power / Re: H-bridge BJT problem on: January 27, 2014, 05:17:48 am
Here's a BJT H-bridge circuit - note the two auxiliary transistors than turn on a pair
of high-side and low side switches together (so only two control wires needed) and the
bridge rectifier providing all the flyback diodes in one package smiley



Yes the layout is odd, the arms of the bridge are crossed over X-style in the middle,
and you have to tune the values of R5 and R6 according to the supply voltage and
the gain of the transistors.

The two control lines must not be pulled HIGH simultaneously, this circuit has
no shoot-through protection for that.

I tried this circuit using BD139,BD140 and 2n4401 and it works perfectly ! ! thank you
5  Using Arduino / Motors, Mechanics, and Power / Re: H-bridge BJT problem on: January 26, 2014, 12:06:21 am
Something with reasonable ratio between Ic and Ib at saturation (ie more like 30--50
than 5--10).

what can u say about this circuit i will use 12V instead of 9V. same transistor to be used.

6  Using Arduino / Motors, Mechanics, and Power / Re: H-bridge BJT problem on: January 24, 2014, 08:09:29 am
omg. I dont know that.

what transistor should i use.
7  Using Arduino / Motors, Mechanics, and Power / Re: H-bridge BJT problem on: January 24, 2014, 04:39:52 am
I really cant get it to work Im using TIP31C and TIP32C
im using this circuit
http://www.robotroom.com/BipolarHBridge/BipolarHBridgeSchematic.gif
I use 220ohm resistor

also when i try to configure TIP32C , 12V in emitter motor in collector its always on even its grounded or in 5V signal it will of only wen i disconnect the source in the base
8  Using Arduino / Motors, Mechanics, and Power / Re: H-bridge BJT problem on: January 23, 2014, 06:47:06 am
Here's a BJT H-bridge circuit - note the two auxiliary transistors than turn on a pair
of high-side and low side switches together (so only two control wires needed) and the
bridge rectifier providing all the flyback diodes in one package smiley



Yes the layout is odd, the arms of the bridge are crossed over X-style in the middle,
and you have to tune the values of R5 and R6 according to the supply voltage and
the gain of the transistors.

The two control lines must not be pulled HIGH simultaneously, this circuit has
no shoot-through protection for that.


Hi,, im gonna use this .. for a 12V supply and 5V PWM signal should i use power transistor like TIP31C and TIP32C or I can just use 2n3906 and 2n3904..
you say R5 and R6 will tune the hbridge but how can i compute it to have atleast 100mA current flowing... is the value of R1-R8 except R5 and R6 fixed in 4.7kohm?
9  Using Arduino / Motors, Mechanics, and Power / Re: H-bridge BJT problem on: January 12, 2014, 07:12:06 am
Here's a BJT H-bridge circuit - note the two auxiliary transistors than turn on a pair
of high-side and low side switches together (so only two control wires needed) and the
bridge rectifier providing all the flyback diodes in one package smiley



Yes the layout is odd, the arms of the bridge are crossed over X-style in the middle,
and you have to tune the values of R5 and R6 according to the supply voltage and
the gain of the transistors.

The two control lines must not be pulled HIGH simultaneously, this circuit has
no shoot-through protection for that.

I cant understand well the circuit... where should i put the motor and can it be control using PWM
10  Using Arduino / Motors, Mechanics, and Power / Re: H-bridge BJT problem on: January 12, 2014, 12:14:45 am
Thank you for all the reply.. 
If i use the combination of PNP and NPN how can i fully turn it on using 5V signal? should i use MOSFET instead?
11  Using Arduino / Motors, Mechanics, and Power / H-bridge BJT problem on: January 11, 2014, 05:21:45 am
Hi, I want to control a single motor using H bridge ( 4x 2n3904) but the problem is I cant increase the current flowing on my motor even I decrease the Rb the transistor just overheat...  I have 12V transistor supply and a 5V driving voltage

heres my circuit



I want to have atleast 100mA flowing on my motor... in the circuit i replace the motor with resistor equivalent since when i run the motor through a direct 12V the current is about 94~100mA...
12  Using Arduino / General Electronics / Re: problem in dc motor need a push to start on: June 05, 2013, 08:40:08 am
Quote
4x 1.2v battery is enough right?
Want me to say it again, no.
According to the data sheet Vs has to be at least the same value as Vss. In your case it is less.

Quote
i use this schematic
That is not a schematic, that is a physical layout diagram and as such is useless for talking about the circuit.
You have no diodes, while that will not stop it from working it will cause problems / damage to the other components in the circuit.



where should i place the diode. i thought it has a diode already.
13  Using Arduino / General Electronics / Re: problem in dc motor need a push to start on: June 05, 2013, 06:36:21 am
i use this schematic


4x 1.2v battery is enough right? i tried using 9V battery with 350mah its working fine but so fast not good for my project.
14  Using Arduino / General Electronics / problem in dc motor need a push to start on: June 05, 2013, 04:17:34 am
Hi, I'm making this obstacle collision avoidance robot and I'm having a problem in the dc motor, I used this motor (FA-130 Tamiya motor). I'm not using a motor shield, I'm using this L293D ic to drive the motor with input 4x 1.2V panasonic rechargable battery 2400mah. I need to spin the motor first before it runs own its own.
15  Using Arduino / Displays / Re: LCD 16x2 1602A cant get to 16letters on: April 15, 2013, 12:22:10 pm

i think the problem on that one is that it is only showing the 8 left chars while mine is showing the 2message on both half
Pages: [1] 2