Single ended Practical Sensor Amplifiers Circuit with Op-Amp

Dear all hands

Some time when we want to measure a signal we must amplify it before we can measure it. To amplify signal we can use sensor amplifier. Sensor amplifier can easily constructed from op-amp or we can use certain linear amplifier IC devices.

Practical sensor amplifier topology is divided in two category , that is:

1. Single ended practical sensor amplifier
2. Differential practical sensor amplifier
3. Isolated practical sensor amplifier

Figure below show single ended practical sensor circuit with op-amp :

Basically single ended practical sensor amplifier above is inverting amplifier. Its called single ended practical sensor amplifier because in this practical sensor amplifier its input mode is not in differential mode (output from sensor its referenced to ground not with another signal).

Main drawback of this practical sensor amplifier is that it hasn’t very high input impedance. Gain of this sensor amplifier circuit is : -(R2/R1).

But if we need single ended practical sensor amplifier with very high input impedance we can use another single ended practical sensor amplifier as depicted below :

High impedance single ended practical sensor amplifier circuit above basically is a non inverting amplifier, its has very high input impedance and its gain is : 1-(R2/R1)

Voltage to Current Converter with LM741

Dear all hand

Sometime for BJT biasing purpose we often need a V-I converter, this circuit intended as current supply for the BJT. From academic book we know that there are two kind of V-I circuit:

1. Floating load

2.Non floating load

Making your self tachometer based on LM2907 /LM2917

Dear allhand

After i make F-V converter with LM331 , now i wanna make this converter with more dedicated IC the LM2709 ic, below is the pic

Even this circuit maybe just stright forward from application note but we must make sure that pulses fom rotary encoder fall beyond treshold voltage in pin 11.

Hand made adaptor

Few days ago i made an adaptor (AC to DC tool), and i itended to use it for my AVR modul.

Below is the circuit ( In ISIS proteus):

This circuit use LM7805 and 7812 as voltage regulator and use by pas transistor (MJ2955) for current booster , so it deliver more than 1,5 A .

Below is the PCB:

LM331 Frequency to voltage converter circuit design with simulation in Proteus

Dear al hands, Im sorry this post is moved to :http://ourlibro.com/2011/07/08/lm331-frequency-to-voltage-converter-circuit-design-with-simulation-in-proteus/

INterfacing: Paralel Port Interfacing with PPI 8255

Iam sorry, now this post moved to:http://ourlibro.com/2011/07/07/interfacing-parallel-port-interfacing-with-ppi-8255-circuit/

Make your self Thermocouple Signal Conditioning

Dear all hands,
Thermocouple i think is a most hard transducer to deal with it, but because its temperature range and aviabillity to make by ourself, termocouple still in wide use. In short list, signal conditioning for termocouple must has figure of merit like that :

1. Good CMMR at reasonable gain, usually above 90 db.

2. Has thermal compensation capability.

We can use precision op-amp for this need and use a another temperature transducer for thermal compensation. Precision op-amp like CP07 and zenner diode sometime is adequate.

Four years ago i used thermal compensation like suggested by national semiconductor , below is the circuit:

This circuit use LM335 , a themperature transducer (Kelvin), and for amplification we can use CPo7 in output terminal.

Making Your double side PCB by Yourself

Its very interesting if we can make double side PCB by ourself. And ussually do it when i make my project. This tutorial Im intended for any body who want make their own PCB.
Material you will need :
1. Double side PCB , i sugest you to use fibre PCB
2. Plastic paper for laser printing
3. PCB drill, water spray (that can spray in moist mode)


After you has all this stuff, and then you ready to follow this step:

1. Prepare your PCS silkscreen, and print them with laser print (plastic paper) , dont forget to use mirror printing.
2. Prepare the blank PCB, and lay out the plastic paper on the blank PCB , you can do this for the bottom side first.
3. And the iron it , be carrefull , you must keep it so it isn melt.
4. Use water spray to spray the ironed PCB, spray with gently
5. Plastic paper will release by itself.
6. Now you can make hole for mark the top side
7. Do step 1 to 5 again to finish top side.
8. And ready for PCB etching.
9. Good Luck