how to eliminate noise for ttl logic input

[syarif3682]

ttl noise

i build electronic switch with LS7473 jk flip flop togle circuit for switching solenoid and ac motor,but when ac motor on,all digital switch off by him self each time ac relay for motor energized,please help me to solve the problem.thanks before

 

[ehsanelahimirza]

noise in ttl

it may the problem of high current flowing through the relay. try using another separate supply for relay.

 

[syarif3682]

noisy switch input

i have try to separate the power supply of relay,but that not solve the problem,each 220vac relay energized the ls7473 togle switch reset by him self,is there anything wrong that i miss?

Added after 13 minutes:

for ttl ic i use 7805 and for relay 12vdc i use 7812 and for relay 24 v i use 7824,for relay driver i use ULN2004,for each solenoid i put diode parallel to solenoid coil,and for 220vac relay to switch the 220vac motor i put 24vdc relay to energized that 220vac relay.is there something wrong ?

 

[nandhu015]

why using low pass filter to eliminate noise

Try using capacitors at the input

Regards
Nandhu

 

[syarif3682]

how to eliminate noise.com in the circuite

can u tell me please the value of the capasitor for the ic input,if i put capasitor it seem look like a lowpass filter,is that true ? but what the cut off frequencies i must build for ic input ? please tell me the formula to count the low pass filter.thanks before

 

[nandhu015]

ttl solenoid switching

There is no specific value. It depends on the speed of input you need. Just check with different values to get proper results

Regards
nandhu

 

[saeed_pk]

how to eliminate noise created by relay

Do you have a common DC GND for TTL IC and Relay?
if yes
then you have to connect a reverse biased diode in parallel with relay's energizing inductor