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Faster the better, there’s no criteria. However it should not have like more than 5 sec delay.
High power switch
- Thread starter anikseng
- Start date
You'll find out as soon as you submit it for EMC testing!
How will this circuit affect the Electronagnetic environment?
Via its power connections or emissions from any wires that connect to the output.
RF amplifiers are normally designed to feed a load with a fixed impedance. Is your amplifier specified in this way ? With 1 actuator connected ist will see a load of 2000 ohms. with all 20 connected it will see a load of 100 ohms. High power RF transmit / receive relays may do what you want.
Les.
Les.
No the actuators are actually fabricated by us only.
So you must have a design spec, to which you fabricate them.
Yes, the actuator resistance at resonance is close to 100ohm. The Piezo 1, Piezo 2 .... Piezo N combine (if all all of them working together) would make a resistance of 100 Ohm. I know it's confusing. Thats what we have observed.
Do you need to vary the amplitude to them, or just switch them on and off?
MisterBill2
- Joined Jan 23, 2018
- 27,522
That voltage and power level are within the specifications of a high voltage reed relay, and so that is what I recommend. Then the control is much simpler and also the shielding for EMC is much simpler.Also the leakage current will be much less.
Certainly shielding will be needed as that frequency is in the middle of the AM broadcasting band.
Certainly shielding will be needed as that frequency is in the middle of the AM broadcasting band.
RE:<<SFAT is just a Piezoelectric actuator. (..) As far as I understand TRIAC is a (..) My supply would be a 400V sinusoidal signal of 1MHz frequency>>
Oops! Then why it are 20 pieces? Probably You are willing to change the voltage on SFAT let it open gradually. Then more economic is to design one single SMPS where just PWM is shifted.
Or indeed them are 20 different SFAT in separate places but then why the 1 MHz. It must or open or shut. So I am making a quess You are trying to make a some sort of ultrasonic actuator. Then for sure the oscillator is separate for each actuator and would be dumb to settle them on one 30 kW oscillator if to make a 20 oscillators by 1.6 kW is sure cheaper. And, taking in account that piezo US actuators all are HV systems, the Clapp circuit would be best choice.
More, the 100 Ohms for piezo systems is sth rather unique, as mostly them have a MOhm scale impedance. Yet probably actuators will be heavily loaded, but anyway, V=100 Ohm * 4 Amp=400 V. Probably enough if piezo element stake is rather short. My experience is about 20-30 pieces in the stake and then Voltage is ca 2...3 kV. Let take seriously what means 1.6 kW at 1 MHz. That is the level where short wrong motion into the irradiated place may kill man in millisecond. Be extra cautious. By the way, any relay contacture will arcing at RF, thus may not use an ordinary contactors.
Thus, You ought to disclose bit more about aim/composition of circuit.
RE:<<So you must have a design spec, to which you fabricate them>> - That ir nude theorysation because at praxis one is baking in the hot press the powder having in the shelf or best case buying the separate tablets and gluing them together in the hot press. There are never existing any datasheets when target is small series with DIY rods. Simply one make it and then measure what he got. Have produced such countless times at eighties. My first task in the University was to make then 200 pieces ultrafast carrier gas mixers for epitaxy machinery. All was the hand job.
RE:<<How will this circuit affect the Electronagnetic environment?>> However there exists the numerous standards like
CENELEC ES 59005, 1998
ENC 50166.2: 1995
ANSI / IEEE C95.1-1992
FCC 1996
russia GOCT 12.1.002-84 etc etc,
yet the ultimate basis for them all all all as well the ultimative clarification may be found at monography issued by ICNIRP. First redaction 1995, then 2005, 2010 and 2020. Just read it through, its publicly available free of charge at ICNIRP website.
Specifically to GHz range frequencies is said <<To the values of P = 10 mW/cm2, the thermal effects are weakly expressed.
When exceeding the value of P = 10 mW/cm2 (the value of which in accordance with international standards
is the maximum permissible when the exposure time does not exceed 6 minutes), the influence of the
exposure time becomes decisive and under reaching P = 100 mW/cm2 mortally dangerous to humans.>>
Oops! Then why it are 20 pieces? Probably You are willing to change the voltage on SFAT let it open gradually. Then more economic is to design one single SMPS where just PWM is shifted.
Or indeed them are 20 different SFAT in separate places but then why the 1 MHz. It must or open or shut. So I am making a quess You are trying to make a some sort of ultrasonic actuator. Then for sure the oscillator is separate for each actuator and would be dumb to settle them on one 30 kW oscillator if to make a 20 oscillators by 1.6 kW is sure cheaper. And, taking in account that piezo US actuators all are HV systems, the Clapp circuit would be best choice.
More, the 100 Ohms for piezo systems is sth rather unique, as mostly them have a MOhm scale impedance. Yet probably actuators will be heavily loaded, but anyway, V=100 Ohm * 4 Amp=400 V. Probably enough if piezo element stake is rather short. My experience is about 20-30 pieces in the stake and then Voltage is ca 2...3 kV. Let take seriously what means 1.6 kW at 1 MHz. That is the level where short wrong motion into the irradiated place may kill man in millisecond. Be extra cautious. By the way, any relay contacture will arcing at RF, thus may not use an ordinary contactors.
Thus, You ought to disclose bit more about aim/composition of circuit.
RE:<<So you must have a design spec, to which you fabricate them>> - That ir nude theorysation because at praxis one is baking in the hot press the powder having in the shelf or best case buying the separate tablets and gluing them together in the hot press. There are never existing any datasheets when target is small series with DIY rods. Simply one make it and then measure what he got. Have produced such countless times at eighties. My first task in the University was to make then 200 pieces ultrafast carrier gas mixers for epitaxy machinery. All was the hand job.
RE:<<How will this circuit affect the Electronagnetic environment?>> However there exists the numerous standards like
CENELEC ES 59005, 1998
ENC 50166.2: 1995
ANSI / IEEE C95.1-1992
FCC 1996
russia GOCT 12.1.002-84 etc etc,
yet the ultimate basis for them all all all as well the ultimative clarification may be found at monography issued by ICNIRP. First redaction 1995, then 2005, 2010 and 2020. Just read it through, its publicly available free of charge at ICNIRP website.
Specifically to GHz range frequencies is said <<To the values of P = 10 mW/cm2, the thermal effects are weakly expressed.
When exceeding the value of P = 10 mW/cm2 (the value of which in accordance with international standards
is the maximum permissible when the exposure time does not exceed 6 minutes), the influence of the
exposure time becomes decisive and under reaching P = 100 mW/cm2 mortally dangerous to humans.>>
Last edited:
MisterBill2
- Joined Jan 23, 2018
- 27,522
Certainly this is a high powered system, but certainly within the capability of reed relay switching.
What is not clear is if this is for a one-off creation or if this will be a product produced in quantities and sold. And now a question, as it seems that the intended application is to produce a focused acoustic ultrasonic sound beam. Coupled with the apparent lack of concern about radiation of interference, I am suspecting that this may be a weapon system of some kind. For an industrial process there would be concerns about emissions.
What is not clear is if this is for a one-off creation or if this will be a product produced in quantities and sold. And now a question, as it seems that the intended application is to produce a focused acoustic ultrasonic sound beam. Coupled with the apparent lack of concern about radiation of interference, I am suspecting that this may be a weapon system of some kind. For an industrial process there would be concerns about emissions.
