amitpatel_be
New Member
we are developing Fire pulse circuit , which operate the piezo printer head (128 Nozzle or channel ) have following specification.
1. Pulse Amplitude between 100 to 140V DC
2. Pulse width 5 to 8 Microseconds.
3. Slew Rate 80V per microseconds
4. Clock frequency is 5 to 8 MHz
5. Drive current per channel = 1.024 amp
Calculation of Capacitive load used by single piezo printer head
To calculate the equivalent capacitive load of the PZT, the current for each channel is determined as:
i = C dV/dt
Using values of 100 pF and a slew rate of 80 V/μsecond:
Cjet = 100pF
dV/dt = 80 V/us (Slew Rate)
Therefore:
Ijet= (100 pF) x (80 V/us)
ijet = 8.0 mA (capacitance for a channel)
Now
suppose at present i want to drive 128 channel then The current going
through chip is then calculated by multiplying the current draw from
a jet by the number of jets per chip which is 128:
ichip = ijet x 128
ichip = 1.024 Amps
So from above calculation , for single piezo printer head take 1.024
Amps.
we had developed fire pulse circuit using Fast switching mosfet (IRF640 and other ) , but it was fail to provide a result . Anybody have any solution then suggest to me.
we wait for your reply
Regards
1. Pulse Amplitude between 100 to 140V DC
2. Pulse width 5 to 8 Microseconds.
3. Slew Rate 80V per microseconds
4. Clock frequency is 5 to 8 MHz
5. Drive current per channel = 1.024 amp
Calculation of Capacitive load used by single piezo printer head
To calculate the equivalent capacitive load of the PZT, the current for each channel is determined as:
i = C dV/dt
Using values of 100 pF and a slew rate of 80 V/μsecond:
Cjet = 100pF
dV/dt = 80 V/us (Slew Rate)
Therefore:
Ijet= (100 pF) x (80 V/us)
ijet = 8.0 mA (capacitance for a channel)
Now
suppose at present i want to drive 128 channel then The current going
through chip is then calculated by multiplying the current draw from
a jet by the number of jets per chip which is 128:
ichip = ijet x 128
ichip = 1.024 Amps
So from above calculation , for single piezo printer head take 1.024
Amps.
we had developed fire pulse circuit using Fast switching mosfet (IRF640 and other ) , but it was fail to provide a result . Anybody have any solution then suggest to me.
we wait for your reply
Regards