Hi all,

I have a trigger(pulse) signal of 8V @ohm, but sensor to be connected requires trigger signal of 60-70V @150 ohm, What should i use for voltage amplification of trigger signal.

Regards,
Mukund

 

Hi all,

I have a trigger(pulse) signal of 8V @ohm, but sensor to be connected requires trigger signal of 60-70V @150 ohm, What should i use for voltage amplification of trigger signal.

Regards,
Mukund

You should be able to do it with a comparator and a couple of MOSFETs, like this, maybe:

but you need to specify the rise time, the fall time, and the width of the input pulse and the required rise and fall times of the sensor's input.

Also, you need to specify whether that 150 ohms you mention is the amplifier's output impedance or whether that's the load impedance. I've drawn it so the load impedance is 150 ohms, and the load is shown as R5 on the schematic.

 

Thanks EM Fields,

Rise time of input trigger signal is <= 30 ns
Pulse Width 0.3 -5us
150 ohm is load impedance.
I have 24V DC power available right now, what should i use to have 70V DC supply.

Regards,
Mukund

 

Hi all,

I have a trigger(pulse) signal of 8V @ohm, but sensor to be connected requires trigger signal of 60-70V @150 ohm, What should i use for voltage amplification of trigger signal.

Regards,
Mukund

A bit more info would help - photoflash triggers keep it as simple as possible and usually use a TO92 size SCR in a capacitor discharge arrangement. Something from the 2N5061 family should directly handle the voltage you need, but you'd normally use a pulse transformer - so there's not much restriction on the pulse voltage you can get.

There are various other 4 layer trigger devices that may solve it, the programmable unijunction is one. A PUT oscillator biased just short of self operation can be triggered at the drop of a hat. A PUT is basically an SCR with the gate at the wrong end - turn the circuit upside down and you can do the same thing with an SCR. All the polarities will be reversed, but the principle of operation is the same.

 

A bit more info would help - photoflash triggers keep it as simple as possible and usually use a TO92 size SCR in a capacitor discharge arrangement. Something from the 2N5061 family should directly handle the voltage you need, but you'd normally use a pulse transformer - so there's not much restriction on the pulse voltage you can get.

There are various other 4 layer trigger devices that may solve it, the programmable unijunction is one. A PUT oscillator biased just short of self operation can be triggered at the drop of a hat. A PUT is basically an SCR with the gate at the wrong end - turn the circuit upside down and you can do the same thing with an SCR. All the polarities will be reversed, but the principle of operation is the same.

Schematic, please?

 

Thanks EM Fields,

Rise time of input trigger signal is <= 30 ns
Pulse Width 0.3 -5us
150 ohm is load impedance.
I have 24V DC power available right now, what should i use to have 70V DC supply.

Regards,
Mukund

A boost converter.

 

Schematic, please?

They're all over the internet - ICBA re-inventing the wheel.

 

Thanks EM Fields,

Rise time of input trigger signal is <= 30 ns
Pulse Width 0.3 -5us
150 ohm is load impedance.
I have 24V DC power available right now, what should i use to have 70V DC supply.

A constant - voltage 70 volt supply with a 24VDC input.

Regards,
Mukund

 

Hi EM field,

I have tried your schematic, but as i take pulse period less than 1 ms, response of power mosfet is not proper as below,
Can you please suggest what should be changed to get it proper.






Regards,
Mukund

 

Hi EM field,

I have tried your schematic, but as i take pulse period less than 1 ms, response of power mosfet is not proper as below,
Can you please suggest what should be changed to get it proper.



View attachment 127015




Regards,
Mukund

Sorry, I can't.

 

Hi EM field,

I have tried your schematic, but as i take pulse period less than 1 ms, response of power mosfet is not proper as below,
Can you please suggest what should be changed to get it proper.



View attachment 127015


Regards,
Mukund

Maybe with a little driver.

I just used available components in spice.

 

Maybe with a little driver.
View attachment 127049
I just used available components in spice.

Very nice!

 

Very nice!

What about Vgs for M1 during turn on?

 

Whai about Vgs for M1 during turn on?

 

What about Vgs for M1 during turn on?

LTspice is available free at: http://www.linear.com/designtools/software/

 

Hi
I tested this for 70V and works ok. now i need to vary my output pulse voltage to vary from 30V to 70V, i have 30 to 70 V varying supply, what can i do in this circuit to change the mosfet output pulse voltage to vary from 30V to 70V. VGS of power mosfet is 20V.