Switch to reset charge amplifier

Started by Geoffrey in sci.electronics.design10 years ago 19 replies

Hi there I have a charge amplifier, used to amplify the signal from a piezo electric transducer, with 2nF of reference capacitance shunted...

Hi there I have a charge amplifier, used to amplify the signal from a piezo electric transducer, with 2nF of reference capacitance shunted with 1GOhm. I need to be able to reset the amplifier, preferably with a solid state device (the circuit has to be very compact, and operate in a high-vibration environment). One possibility which comes to mind is to simultaneously short the amplifier ou...


Class G amplifier efficiency

Started by amal banerjee in sci.electronics.design3 years ago 21 replies

Could some electronics guru here clarify this a bit ? The efffiiciency definition for an amplifier is Power delivered to load/DC power supplied...

Could some electronics guru here clarify this a bit ? The efffiiciency definition for an amplifier is Power delivered to load/DC power supplied by power source The Dc power supplied from power supply is Vdc x avg. DC current flowing into amplifier However, Vdc changes, as per design requirements of class G amplifier. So what then would be the efficiency defintion for a class G amplifier. ...


Antenna Amplifier Noise Figure

Started by rickman in sci.electronics.design7 years ago 88 replies

I read this post in an antenna group and I don't get how this guy is coming up with a negative noise figure. Looks to me like he is...

I read this post in an antenna group and I don't get how this guy is coming up with a negative noise figure. Looks to me like he is calculating the noise figure of a resistor, not the amplifier. Anyone care to explain this to me? The part that seems bogus is this... > The negative NF is defined as the amplifier noise being less than the > increase in noise due to the amplifier gai


RF amplifier stability question

Started by amal banerjee in sci.electronics.design2 years ago 6 replies

The standard treatment of amplifier stability is based on small signal S parameters, and involves conditional stability, unconditional...

The standard treatment of amplifier stability is based on small signal S parameters, and involves conditional stability, unconditional stability, Rollet's criterion, etc., What about steady state amplifier operation, is there an analytical way to estimate this ?


10W amplifier, 2.2-2.4GHz

Started by Joel Koltner in sci.electronics.design14 years ago 10 replies

Anyone have an off-the-shelf 2.2-2.4GHz amplifier they like? ~10W is what I'm after. Mini-Circuits has their ZHL-30W-252+ which would be fine,...

Anyone have an off-the-shelf 2.2-2.4GHz amplifier they like? ~10W is what I'm after. Mini-Circuits has their ZHL-30W-252+ which would be fine, although at $3k I'm continuing to do a bit of searching... (And before anyone asks, no, I'm not building a high-power WiFi amplifier and, yes, I do have the appropriate FCC license to put this thing on the air -- with various restrictions on t...


Is cklass B amplifier BOTH linear and non-linear

Started by amal banerjee in sci.electronics.design3 years ago 5 replies

Seeking the opinions of gurus on this newsgroup. The bare bones class B amplifier has zero base|gate bias. A class F amplifier is an extension of...

Seeking the opinions of gurus on this newsgroup. The bare bones class B amplifier has zero base|gate bias. A class F amplifier is an extension of the class B with harmonic tuning. So, is class B linear or non-linear.


Regarding amplifier efficiency

Started by amal banerjee in sci.electronics.design3 years ago 7 replies

Could some electronics guru here please clarify this a bit ? I have been experimenting SPICE RF amplifier designs in my spare time,and I am...

Could some electronics guru here please clarify this a bit ? I have been experimenting SPICE RF amplifier designs in my spare time,and I am getting confused by the differences between textbook expressions for amplifier efficiency etc., and my experimental findings. Consider the textbook definition for efficiency as: efficiency = Power delivered to load/DC power supplied First, the p...


HF amplifier purchase

Started by Klaus Kragelund in sci.electronics.design3 years ago 31 replies

Hi I need to drive a coil with 40Vpp at 10kHz to 20MHz for a test Tried to find gear that would do that, but they all have 50 ohms output...

Hi I need to drive a coil with 40Vpp at 10kHz to 20MHz for a test Tried to find gear that would do that, but they all have 50 ohms output Anyone got a link for a amplifier that can do this? Thanks Klaus


Opto in amplifier screws up output

Started by Fibo in sci.electronics.design7 years ago 21 replies

Hello, I'm trying to make a voltage controlled amplifier. I only need a gain of about 11 max. So I thought I would use an opto as a variable...

Hello, I'm trying to make a voltage controlled amplifier. I only need a gain of about 11 max. So I thought I would use an opto as a variable resistor on an inverting amplifier. I went with the H11F3M https://www.fairchildsemi.com/datasheets/H1/H11F3M.pdf I built up the Automatic Gain Control circuit in the datasheet. I used a 50k resistor as my feedback resistor. When I fired it up, my...


Amplification factor for common emitter amplifier

Started by amal banerjee in sci.electronics.design3 years ago 70 replies

Is it possible to calculate the amplification factor for an amplifier,, e.g., a common emitter amplifier. This is because the amplification...

Is it possible to calculate the amplification factor for an amplifier,, e.g., a common emitter amplifier. This is because the amplification depends very much on the biasing condition, and so without a SPICE simulation, it appears impossible to determine the amplification factor. Am I right/wrong.


Common collector amplifier and amplitude modulation

Started by Anonymous in sci.electronics.design3 years ago 20 replies

Could some electronics guru here shed some light on this Could a single stage common collector amplifier exhibit amplitude modulation ? I have...

Could some electronics guru here shed some light on this Could a single stage common collector amplifier exhibit amplitude modulation ? I have the SPICE model of a simple common collector amplifier consisting of two base bias resistors, a collector resistor and an input and a output DC blocking capacitor, as well as a source and a load resistor of 50.0 Ohm. The BJT collector is connected to ...


Class E amplifier question

Started by amal banerjee in sci.electronics.design3 years ago 5 replies

Here is a question for all electronics gurus here. Can a class E amplifier be termed efficient - given the shunt capacitor from BJT collector...

Here is a question for all electronics gurus here. Can a class E amplifier be termed efficient - given the shunt capacitor from BJT collector to ground, which is an AC short -- unless the capacior value is very small, such that the capacitive reactance is large. Any flaws in this argument ?


Small Design Error Saga

Started by Phil Allison in sci.electronics.design3 years ago 3 replies

Hi to my many friends, ----------------------- this story involves local Sydney electronics maker Jands, a few years ago. I know...

Hi to my many friends, ----------------------- this story involves local Sydney electronics maker Jands, a few years ago. I know Jands quite well, been to their factory many times. I know the particular amplifier, the SR3000, rated at 1500W per channel on music programme. I know the designer, Doug Ford - he has since appeared on U-tube. See pics of culprit amplifier: htt...


Stereo mixer amplifier

Started by Anonymous in sci.electronics.design3 years ago 22 replies

Greetings, An article about my stereo mixer-amplifier project is now available. http://crcomp.net/electronic/mixeramp/index.php Thank...

Greetings, An article about my stereo mixer-amplifier project is now available. http://crcomp.net/electronic/mixeramp/index.php Thank you, 73, -- Don Kuenz KB7RPU There was a young lady named Bright Whose speed was far faster than light; She set out one day In a relative way And returned on the previous night.


simple opamp amplifier circuit

Started by panfilero in sci.electronics.design10 years ago 23 replies

I'm simulating on LTSpice, a simple amplifier circuit with a 2.5V offset, but if I don't include a capacitor on my input my output hits the...

I'm simulating on LTSpice, a simple amplifier circuit with a 2.5V offset, but if I don't include a capacitor on my input my output hits the rails... why is this? The link shows what I'm doing in LTSpice thanks http://i555.photobucket.com/albums/jj477/panfilero/Capture-1.jpg


Solderless audio amplifier

Started by John Smith in sci.electronics.design9 years ago 40 replies

The radio kit hasn't arrived yet (Thread of 18th Jan. Probably due to weather conditions here in Ontario) so I thought I'd try my hand at making...

The radio kit hasn't arrived yet (Thread of 18th Jan. Probably due to weather conditions here in Ontario) so I thought I'd try my hand at making my own audio amplifier kit. The requirements were as follows: 1. Must use components I already have. I couldn't find any 1N4148 but did find packets of 1N4001 so that's what I used. Also I could only find one resistor under 1 ohm so another is...


Need help to design a transimpedance amplifier

Started by T Obulesu in sci.electronics.design6 years ago 30 replies

Hello guys.. I want to design a trans-impedance amplifier to detect currents of the APD (in the range of 200 nA to 100 micro A). Could some...

Hello guys.. I want to design a trans-impedance amplifier to detect currents of the APD (in the range of 200 nA to 100 micro A). Could some one suggest me the best IC with less bias current, single supply (+5 V only) and how to design a high sensitive TIA..? (typically, for every 100 nA change in the current, 100 mV voltage should be displayed).


LTspice simulation is taking too long to run

Started by MUHAMMAD FAHAD BHUTTA in sci.electronics.design7 years ago 11 replies

Greetings people ! So lately, I have been working on my Sigma Delta ADC and before going advance, I wanted to have a base model WORKING (1ST...

Greetings people ! So lately, I have been working on my Sigma Delta ADC and before going advance, I wanted to have a base model WORKING (1ST ORDER, 3 bit digital output) . The circuit is quite simple. Input (x) -> Difference Amplifier -> Integrator (op-amp) -> Quantizer-> Encoder -> 3-bit Output (Y) -> Feedback DAC to the non-inverting pin of Difference Amplifier (I am using I


AD8066 buffer oscillates with inductor on input

Started by Chris Jones in sci.electronics.design5 years ago 7 replies

Hi all, Someone at work wanted a buffer to drive a coax cable with a signal from a high impedance device. I thought this would be a quick job...

Hi all, Someone at work wanted a buffer to drive a coax cable with a signal from a high impedance device. I thought this would be a quick job so I built a buffer amplifier, using half of an AD8066 configured as a unity-gain buffer. I know that op-amps don't like capacitive loads, so I connected a 50 Ohm resistor between the cable and the buffer amplifier and also terminated the other ...


How to compute base biasing resistor for class C amplifier

Started by amal banerjee in sci.electronics.design3 years ago 9 replies

Could some electronics guru here please tell me how to compute the base biasing resistor for class C amplifier. From the Vce-Ice- load line...

Could some electronics guru here please tell me how to compute the base biasing resistor for class C amplifier. From the Vce-Ice- load line graph, the Q point has to be below the horizomtal axis, i.e., Vce < 0.0. All hints, suggestions are welcome. Thanks in advance.