Proportional solenoid valve

[narithota]

pwm proportional solenoid valve

Hi everybody

I have to control the Proportional solenoid valve (0-24v, 1A) by using 89S51 for flow control according to the feed back signal.

Please suggest some suggestions & information regarding this project

Regards

Nari

 

[FvM]

proportional solenoid valve

A direct PWM drive with several 100 Hz modulation frequency may be a simple solution. It's also used by valve manufacturers drive circuit to reduce hysteresis. The modulation frequency can be adjusted according to the valve's mechanical properties.

 

[narithota]

pwm for proportional valve 24v

hi

Thank for the reply

Can you provide me some hardware related issues?
How to control 0-24V from 5v PWM signal
Please help me regarding the hardware design.

Regards

nari

 

[narithota]

solenoid current feedback

Hai

I want control the proportional solenoid valve 0-24V, 400mA for flow control, for this I am using PWM and generating 1KHz PWM pulses using LPC2106 micro controller
My software is working well
I required some hardware help
How to interface LPC2106 with proportional solenoid, which is suitable for this application transistor or FET or any driver IC .
Voltage is proportional to the flow rate has given in the solenoid data sheet

Please provide hardware details & related sites.


Regards
nari

 

[FvM]

how to control proportional valve using pwm

If no current feedback is intended, a logic-level MOSFET and a free-wheeling diode at the solenoid would be sufficient.

 

[narithota]

valve drive ckt

Hay thanks for the reply
I am not using any current feed back
Please suggest optoisolater to isolate the LPC2106 with driver circuit
I am planning to use L298 H Bridge Driver for my application
Please give me hardware suggestions

Regards
nari

 

[Faizan Jawaid]

solenoid fet driver circuit

Hi...i`ve designed a ckt...Its a PWM mosfet driver and can handle ur 1A solenoid load... Make a PWM FREQ 1Khz source from any MCU...and set its duty cycle according to the flow...

 

[narithota]

solenoid valve provided with free wheeling diode

Thanks for the reply

Presently I am generating 1Kz frequency PWM wave using LPC2106
LPC2106 output high voltage is 3.3V,shell I connect LPC2106 output directly, other wise I have to use the buffer Like 74LS244

Regards
nari

 

[FvM]

proportional valve drive circuit

You should be able to drive the optocoupler from GPIO directly, possibly adjusting the resistors.

I have a remark regarding the power stage. Usual MOSFET have Ugs maximum rating of 20 V, 24 V is definitely too much. With a resistor in parallel to the 2222 driver transistor, you should adjust Ugs down to about 12 or 15 V. Also the BD transistors are a bit oversized, you don't intend to drive a kW switch here.

 

[Faizan Jawaid]

proportional valve pwm mosfet

FVM is right...The Vgs must not exceed 20V...add a resistor 10K parallel to Pn2222

 

[phaedrus]

proportional solenoid hysteresis

How will 10k resistor in || with PN2222 reduce the Ugs of the MOSFET ? Can one clarify ?

 

[Siniša]

1a solenoid

What kind of feedback will you be using?

 

[Faizan Jawaid]

24v ,1a solenoid

How will 10k resistor in || with PN2222 reduce the Ugs of the MOSFET ? Can one clarify ?

A 10K resistor parallel to PN2222 will make the Vbe of the BD transistor half due to voltage divider...So the Vgs will also become half...

 

[rvionics]

solenoid pwm drive fet

Modified circuit as suggested by Mr. FVM



Added after 42 seconds:

Modification suggested by FVM

 

[phaedrus]

proportional solenoid

Hi Rvionics,

Couple of queries :
1)I think FVM suggested to put the resistor across Q4 ( in your diagram ) ? Though your diagram does the same thing.
2) Should'nt Q1 and Q2 be complementary pairs ?
3) Isnt it better to decouple the solenoid with a capacitor too ?

I was reading this :
**broken link removed**.

A bit off topic ( but I think the OP is not following anyway)
How does the turn on and turn off time affect the MOSFET( other than the EMI/RFI aspect ). Generally I think the turn off time is kept faster ? Any thumb rules for working it out ?

 

[FvM]

h-bridge proportional valve

Hello phaedrus,

1. I actually imagined a partly different circuit, but the suggested circuit is profound and I didn't see a reason to contradict. A voltage divider with a resistor in parallel to the 2N2222 (Q4) allows to adjust the gate voltage without a zener diode. The dynamic losses at Q1 are somewhat increased. Both variants are possible, I think. If the supply voltage is varying, the zener diode will achieve stable conditions.

The R4 series resistor is a good thing, generally.

2. There are complementary transistors in all discussed circuits, I think

3. Basically yes.

Your questions aren't off topic, but go beyond the original question I think. Some consideration aren't necessary for the said application, but meaningful when discussing more critical (higher power and frequency) applications.

The Zetex application mentions a possible reduced turn-on speed. I think, for general applications, a symmetrical gate waveform is most common, e. g. with SMPS circuits. A special reason to reduce the turn-on speed is to limit the diode reverse recovery current, which is possibly the strongest EMI source and may seriously reduce the breakdown voltage margin of the involved devices.

The turn-on series resistor can be increased by trial, until gentle current and voltage waveforms are achieved.

For the rather low PWM frequencies of a proportional valve driver, even the push-pull gate driver could be probably omitted.

 

[phaedrus]

Hi FvM ,

The R4 is sometimes mandatory.
I had a problem when I omitted it when using a TC4420 to drive a IRFP250 which was driving a flyback txfer. The output voltage was lower and used to vary when I bring my finger close to the MOSFET.
I put a 150E in series and the problem vanished.

Cheers.

 

[Siniša]

Look at this **broken link removed**. Note the dither frequency generator on block diagram. Hope it helps.

 

[kovibb]

Re: pwm proportional solenoid valve

Hi everybody

I have to control the Proportional solenoid valve (0-24v, 1A) by using 89S51 for flow control according to the feed back signal.

Please suggest some suggestions & information regarding this project

Regards

Nari

Please what exactly type of solenoid did you use?

 

[kovibb]

Re: pwm proportional solenoid valve

Hi

I have also one question to you. Can I joint this two circuits (A3942 and **broken link removed** afraid of damage or oscillation? It is connection between switched supply and solenoids driver. Load in one branch is 60ohm resistor and cca 10mH inductance. please help me or give me advice. Thank you