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Circuit drawing and Parts list
of a-stable multivibrator

The drawing of right is the circuit drawing of the a-stable multivibrator which I made this time.

IC1 is the main part. It is the integrated circuit called 'Inverter'.
D3 and D4 are Light Emitting Diodes. Those flash alternately.
IC2 is the three terminal regulator. It makes the stable 5V from 12V input.

Parts list

Note1

The inverter is the circuit which becomes the output is LOW(0V) when the input is HIGH(+5V), the output is HIGH(+5V) when the input is LOW(0V).
There are LS type and HC type as low power consumption in SN7404.
It isn't possible to use the HC type for the circuit this time, because it is made with the CMOS and the input electric current doesn't flow.
When making this page first, I wrote that HC type is possible to use because it was the inverter. However, I found that it isn't possible to use when confirming that the circuit works. I attempted to experiment but there was not still normal operation. At first, it seems to be working normally but the red and green LEDs have lit up at the same time in case of being for a while.
This time, I am using LS type.
As for the arrangement of the component lead, see 'pin assign'.


Note2

This is the IC that obtains the output of 5V from the power supply of 12V.
As for the arrangement of the component lead, see 'Component lead of three terminals voltage regulator'.


Note3

This is a transistor that drives the LED.
If open collector type is used as IC1(e.g.7405) this part does not need.
As for the arrangement of the component lead, see 'Component lead of the transistor'.


Note4

The switching diode is used.
As for appearance, see the page of the 'diode'.


Note5

The cheap red color, green color is used.
As for appearance, see the page of the 'Light Emited Diode'.


Note6

The cheap carbon film resistor is used.
The tolerance of the resistance value is not important.
As for a little more detailed explanation, see the page of 'resistor'.


Note7

The electrolytic cpacitor is used.
As for the details, see the page of 'capacitor'.


Note8

The multilayer ceramic capacitor is used.
As for the details, see the page of 'capacitor'.


Note9

This is IC socket for SN74LS04.
IC can also be attached to the printed board directly.
This time, thinking that IC is used in other circuits, I use IC socket.


Note10

The universal PWB with 25 x 15 holes is used.
As for the universal PWB, see the page of 'printed wiring board'.


Note11

This wire is used for the wiring of the printed board.
It is enough if being 1 m.
As for the tin coated wire,see the page of 'wiring material'.


Note12

Twisted strand wire of the different color is used.
Because there are few currents of this circuit, thin wire is used.
It is enough if being 10 cm.
As for the twisted wire,see the page of 'wiring material'.


Note13

I use this parts to fix the printed board to the case.
I don't house the circuit this time. I am using this part to prevent that the wiring face of the printed board touches metal etc.
The height is about 5 mm. The hexagon form. The upper part is the screw of diameter 3 mm.
Because there is the various type of spacer, you can chose as you like.


Note14

This is a nut that fixes the spacer to the printed board.


Note15

This is not necessary in case that you have the power supply of 12V.
This is the power supply that obtains DC12V from AC100V.
For 100mA is enough.


Note16

The plug is used for the output of the AC adapter.
The connector that fit the plug is prepared.
There are many size of the plug.( Pipe form diameter, Thickness of the central stick )
So, the connector that does fit to pulg needs to be purchased.
You can even to attach the output cord of the AC adapter to the printed board directly, without using the plug.
You need to be careful of plus and minus.