Dear All,
we have made a heat exchanger... in which two ac motor pumps and one AC fan is used to calculated the heat transfer...
we have 7 DS18B20 sensor on one wire.. two flow sensors for hot and cold water supply.
one current sensor to measure current in the fan to with which we have calibrated the air flow rate...
erverything works well....but when we switch of or switch on any motor or fan arduino stop sending data and loses its port.
AC is nowhere connected to arduino all sensor are connected to usb supply only.
do anyone have idea why arduino stops when is is not connected to these AC pump and motor directly.
Thanks in Advance...
Regards
Davinder
Spectrum
How are you driving the motors? Do you have protection or flyback diodes to curtail inductive spikes or are the motors connected directly to the Arduino(bad idea if so)?
Bill
Hi,
How are you switching the motors/fans on/off.
Is all the arduino and sensor wiring away from the motor/fan wiring and switching?
How much power are you switching for the motors/fan?
Motor/fan specs and can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
Tom.... 
tHANKS FOR YOUR REPLY....
Actually we have diagnostic the problem. its due to the emf produced by devices near the controller...
Actually in workshop lots of heavy equipments are working on time.
we have 2 nos of half HP pump.
is there any way to do coding in way that arduino reset itself if it gets some disturbance or anything like that..
because arduino still connected to system even after disturbance...but stop sending data .. can we put a check in coding that if something like that happens ..arduino get restrated.
thanks in advance....
Davinder Saini
Spectrum Technology