l298..!! =(

[usmanyousaf]

Hi IKA,

i m constantly having problm with l298..this time there is very low current output(.1A) in channel B, it doesnot rotate my motor vich needs .4A at max.
i need urgent assistance.

thanks

[ikalogic]

Hi IKA,

i m constantly having problm with l298..this time there is very low current output(.1A) in channel B, it doesnot rotate my motor vich needs .4A at max.
i need urgent assistance.

thanks

pls post your schematic.

are you using current sense resistor? what value?

[usmanyousaf]

i,ve exactly copied http://www.ikalogic.com/shm_hb_l298.php , but i,ve seperated both channels.

no current sensing resistor.

i was trying pwm without opto couplors..!! it was working quite well b4 trying pwm..!!

[ikalogic]

Hello,

well.. if you connect it normal mode (not pwm), what is the votage at the output of the bridge? with the motor? and without the motor?

if there is a BIG difference with and without the motor, then your bridge is most probably dead.

[usmanyousaf]

aww... im getting 22.9V vdout motors and abt zero volt vid motors..=( can u give me some tips abt how can i save ic from being fried...??
and a short tutorial abt using opto coupler.
i have only 2 days till compitition.

thanks for giving ur precious time to my topic.

[ikalogic]

hello

post your schematic with the opto coupler and we can start from here

also, what is the exact rating of your motor?

[usmanyousaf]

im v bignner..i am almost unfamaliar vd optocouplers. this is my first circuit(not mine actually, i just coppied =p). bt i heard opto couplers can save ic from being damaged in pwm mode..!! plzz gimme some usefull hints..!!

[usmanyousaf]

motors are 24 V and require .5A current when at full load..!!

[ikalogic]

mayebe you should start by posting the circuit, or at least a link to it!

[zealonomics]

Hi there, i built an exact circuit from the topic " 4A H-Bridge Using L298 IC" using 10 nF capacitors, C9013 transistors and 1N5408 diodes but the circuit is not working. Any idea why? Thanks..