Technical specifications of electric components are listed in so called datasheets. These are provided by the manufacturers and can normaly be obtained from their homepages. A good search engine for common datasheets is:

Select the line to position the end points Select the line to position the end points Doubleclick the Text Item to set the text Common timer IC Provides a variety of current signals Converts an analog signal into a digital output. Place this in series in the circuit to measure the current flowing. The output is high if and only if all of the inputs are high. Provides a potential-difference. Converts a binary-coded-input to a form displayable by a seven segment display.

Normal operation: lt (Lamp Test) and the rb (Ripple Blanking) are held high, en (Enable) is held low. Bidrectional Light Emitting Diode Holds an internal count, which changes when the clock input > pin is pulsed.

Normal operation: en (Enable) and u/d (Up/Down) are held high, r (Reset) is low. Cleans the logic input, with the output high or low depending on input trigger levels. Merges several connections into one. Stores electrical charge.

The voltage across the capacitor and capacitance are related by Charge = Capacitance x Voltage. A square-wave generator, outputing logical high/low at repeating time intervals. Provides a fixed current source. Displays the current at the probe point on the oscilloscope. The output state is set from the input state when the clock is pulsed. Converts a digital input to an analog output signal. Seperates the input data stream into components. The value of the input is passed to the "X" output selected by the binary number given by the "A" inputs. Allows current to flow in the direction indicated by the arrow when a certain voltage difference has been reached. Double-Pole Double-Throw switch. Double-Pole Single-Throw switch. Point to connect the circuit to an external entity - e.g. a mechanical component or as part of a subcircuit. Provides a fixed voltage point to connect components to. Ground (0V) point The output is the logical inverse of the logic-input state. The output state is set according to J and K when the clock is pulsed. Provides a numeric array of Push-to-Make switches, with 4 rows and a configurable number of columns. Light Emitting Diode Provides a user-adjustable logic state.

Click to pulse high, or drag the mouse off to keep the output high. Shows the logic-state of the input. Compares two binary numbers and generates output to indicate which binary number has the greater magnitude. It has 3 cascading inputs:and 3 outputs: A matrix display of LEDs with a configurable number of columns and rows. Combines the input data stream into one single stream. The value of the input selected by the "A" inputs is passed to the output. The output is low only when all of the inputs are high. The output is high when all inputs are low.

An operational amplifier (opamp) is an integrated universal amplifier which's behaviour can simply be configured by external components. Those high flexibility is achieved due to it's high open loop gain A0 which amplifies the difference of the input potentials. The transfer function is:

The open loop gain A0 is the value of the complex gain A in case of f = 0Hz (d.c. voltage) and is ideally infinite, in praxis depending on type 105 to 107.

The whiched behaviour is achived by feedback of output to the input using discrete components. This way a control loop is closed, which should eliminate control deviation, thus the input voltage UE here. From this it follows that, except for few exceptions, both inputs of a working opamp circuit must have equal potential. This realisation is very useful for calculation and error diagnostics!

In most cases opamps can assumed to be ideal and linear in operating range:

Characteristics of real opamps are listened in it's datasheet.


The output is high when at least one of the inputs is high; or low when all of the inputs are off The pins are divided into 3 registers.

Data Pins

The data pins can be configured as either all input or all output. They are:
Status Pins

The status pins are read-only. They area:
Control Pins
The remaining pins are all ground. The PIC component allows the simulation of a PIC program.

The loadable PIC program must be one of the following formats:Doubleclick on the PIC component to open up the program source file.

If the program source file is of type assembly, then the the opened text file will automatically be linked to the simulation. You can control the program from the text document using the debug controls.

Explanation of buttons: Consists of a resistor connected to the end pins, with a central pin connected at an adjustable point along the resistor Connect this probe the the point in the circuit to measure the logic value. The output will be displayed in the Oscilloscope view. This RAM stores data as a collection of words; each of which contains word size bits of data.

To read data, set the CS (chip select) and the OE (output enable) pins high, and select the word using the address pins A*. The word is outputted on the data-out pins: DO*.

To write data, set the CS (chip select) and the WE (write enable) pins high, and select the address to write to with the A* pins. Write to the selected word using the data-in pins: DI*.

The Address Size is the number of bits that determine an address; so the total number of words stored will be 2^Address Size.

A resistor limits flow of current, obeying Ohms Law which says, that current and voltage are proportional each other. By define proportional coefficient to 1 we get the unit:

Thus these value is a measure how worse a resistor conduct the current. In practice an other measure has established how good current is conducted. For this purpose the reciprocal is generated an a new dimension, the susceptance is introduced:

For better understanding it is allways a good idea to illustrate the practical meaning of such formulas by explaining them in words. That is very easy here:

"A resistor then has a value of 1 Ohm, if an applied voltage of 1 Volt causes a current of 1 Ampere."


Set of resistors with identical values in a Dual Inline Package. Rotary Switch Interface to a serial port. The pins are:
A seven segment display with a decimal point. This can be configured to either have a common cathode or a common anode. A simple filament signal lamp, with a 100 ohms series resistance. Single-Pole Double-Throw switch. Single-Pole Single-Throw switch. The output is made high by holding set high, and low by holding reset high. Stores electrical charge.

The voltage across the capacitor and capacitance are related by Charge = Capacitance x Voltage. Limits the flow of current, obeying Ohms Law Provides a variety of voltage signals. Displays the voltage at the probe point on the oscilloscope. Place this in parallel in the circuit to meaure the voltage between two points. Exclusive NOR gate. Output is low when exactly one input is high. Exclusive OR gate. Output is high when exactly one input is high. Call a subroutine. When the subroutine returns, the code will continue execution from this point. Delay the program execution for a fixed period of time. Doubleclick on the item to edit the embedded code. End the program execution, putting the IC into sleep. Unlike Start, however, this FlowPart is not necessary for proper program execution The code contained in the foor loop is repeatedly executed. By default, the variable used will be incremented every time. This can be changed by entering a value other than 1 into Step.

The for loop will exit when the value contained in the variable is equal to the end value. Gets a key from a keypad connected to the PIC. Assign the value of a port to a variable. Repeatedly execute code, until the given condition is false. The condition is checked after the code has been executed.

This is different from "While", which checks for the condition to be true before the code is executed. Set a pin on a port high or low. The pin needs to be set as an output pin. Output to a Seven Segment display. Determines the initial program execution point. Defines the starting point of a subroutine. Call this subroutine using "Call Sub" Conditional branch point, depending on the high/low state of a pin. A unary operation involves only one variable. Suppo operations are:
Assigns the evaluation of an expression to a variable. The expression can take many forms. For example: Conditional branch point, depending on the comparison of two values. The supported comparisons are: Repeatedly execute code, until the given condition is false. The condition is checked before the code has been executed.

This is different from "Repeat", which checks for the condition to be true after the code is executed. Sets the port's pins state to high/low from the given value. Only pins that have been configured as output pins will take on the value assigned to them.

A transfer-function is a mathematical model of a system. Generally it is given by the division of the resulting output signal to an adequate input signal. By multiplicating this transfer function with any input signal, the input information disappears and we get the output signal.

In the simplest case of a linear SISO system without storage elements the transfer function reduces to a scalar gain. Here any input signal is practical because system behaviour is independent from it.

By adding storage elements the scalar gain becomes a complex gain in frequency domain. This includes information about frequency dependent gain and phase shift in static (i.e. steady state) case. In order to describe dynamic (i.e. transient) behaviour as well we use the transfer function in complex variable domain which also contains information about damping procedure. The adequate input signal here is a dirac impuls which consist of superposition of all frequencys in equal amplitude and thus can worm all needed information out of the system.

This realisation also has very practical meaning, by the way. Given that in practice a shot looks like a dirac impulse in spectrum we can fire a gun in a cathedral for example and record the echo. Now we have the transfer function of the cathedral. When convolve this with any audio recording it will sound like played in the cathedral.