EK011 Pulse generator 555
Part.no: 41015613
EK011 is a pulse generator based around the classic timer IC 555, that is wired as a square wave oscillator with ~50% pulse width. The frequency can be set to different ranges using the jumper and adjusted using the potentiometer. Other frequency ranges can be realized by mounting different capacitors in place of C1 - C6.
- Supply voltage: 3 - 15VDC
- Max. output current: ±200mA
- Frequency ranges: 0.08Hz - 50Hz, 0.8Hz - 480Hz, 8Hz - 5kHz, 80Hz - 50kHz, 800Hz - 500kHz, 8kHz - 900kHz
- Dimensions 34 x 46mm
- Mounting holes: c-c 28 x 40mm, ø2.5mm
Component list
| RefDes | Value | Qty. | Part.no. | Marking |
|---|---|---|---|---|
| HDR | Pin header 2.54mm 2-pin | 8 | 41001167 | |
| C1 | Ceramic 100pF | 1 | 40500124 | 101 |
| C2 | Ceramic 1nF | 1 | 40500030 | 102 |
| C3, C9 | Ceramic 10nF | 2 | 41011998 | 103 |
| C4, C8 | Ceramic 100nF | 2 | 41015538 | 104 |
| C5 | El.lyt 1uF | 1 | 41015174 | 1uF |
| C6, C7 | El.lyt 10uF | 2 | 40520021 | 10uF |
| LD1 | LED 3mm red | 1 | 40307000 | |
| R1 | Resistor 10kohm | 2 | 40811410 | |
| R2, R3 | Resistor 1kohm | 1 | 40811310 | |
| U1 | Timer 555 | 1 | 41015923 | LM555CN |
| DIL socket 8-pin | 1 | 40410008 | ||
| VR1 | Potentiometer 1Mohm | 1 | 41014923 | B1M |
Assembly guide
Before starting assembly, check that the PCB is free from damage and scratches. Verify that all components to be assembled are present, compare with the component list.
It is usually easiest to start assembling the lowest profile components and work upwards in size. IC sockets, resistors, ceramic capacitors and diodes are mounted first. Electrolytic capacitors, connectors and potentiometers are mounted last.
For some components, correct orientation is important. Pay attention to the markings on the PCB.
Interactive assembly guide ↗
Using
When the board is supplied with a voltage from 4.5V to 16V, the timer IC will start and provide a square wave on the output.
The frequency can be adjusted using the potentiometers and set in ranges from high to low by patching in different capacitors. Highest frequency range is obtained by jumpering the top-most pins and the lowest range by jumpering the two bottom-most.
Modifications
The board has a space between the output (OUT) and the timer IC with 9 holes, marked "Proto Area". By breaking the solder jumper on the back side of the PCB, additional components can be soldered in to adjust the output signal.
The top-most three holes are wired together and goes to the output pin. The three holes on the second row are wired to the output of the IC. The bottom three holes are wired to ground.
By soldering a simple resistor and capacitor, one can either adapt the output to audio equipment by AC coupling the signal (picture 1), or low-pass filtering the signal (picture 2).
Simulation ↗
Schematic
Drawing
