Here you can find a collection of electric and electronic circuits realized by the PSpice tool or by Cadence ORCAD Capture Lite.
You can freely download, use or modify all the stuff you'll find here.
Anyone who wishes to collaborate and share his experience, i invited to send, his works.
OrCAD 17.2 PSpice Designer Lite Software, it's freely downlonable, after registation,
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PSpice is a free open source software, download it
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Digital Ramp ADC
Digital Ramp analog to digital converter
The analog to digital ramp was created by a 74163 counter, which generates a digital ramp from 0000 to 1111 (4bit); the digital values are converted to analog by a R-2R ladder DAC and then compared with the analog signal to convert (a sinusoid with offset). The ramp is resetted (via the CLR pin) when its value reaches the analog value to convert. Before resetting, the corresponding digital value should be read. In the attached image, at 4.7 ms we have the first reading 0101 (5 steps). From the same image we can see that the conversion time is proportional to the value to be converted.
Single slope ADC
Linear ramp analogic to digital converter with counter
INTEGRATOR
The integrator OpAmp, generates the linear ramp.
COMPARATOR
The second OpAmp, working as comparator, gives a falling edge (from +Vcc to -Vcc) when the ramp reaches the analogic input.
MONOSTABLE
The falling edge causes a short pulse in the NE555 out.
The pulse closes S1 and discharges C so a new ramp can start.
COUNTER
The pulse put to zero the counter too.
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AM DSB SC modulator
Double Side Band Amplitude Modulation (AM DSB) balanced modulator or ring modulator
The balanced modulator circuit realize the suppression of the carrier (SC) and it's made using diodes. By PSpice is possible to plot the output voltage both in time and frequency (spectrum). To plot the spectrum, just press the 'FFT' key in the plot window.
Per informazioni, segnalazioni od invio materiale: rdr@erredierre.it