Find the logic combination circuit of BCD code to B code 100

Without a single-chip microcomputer, you can only use some of the most basic logic circuits or some chip selection chips (including AND gates, NAND gates, NAND gates, OR gates, 74LS138 139 chips, etc.).

No matter what it turns into, as long as it is not too complicated, you can use the "truth table and Carnot diagram" in analog electronic technology, and then use a sequence of logic circuits to connect according to the resulting Carnot diagram, I don't know if you have learned?

8421bcd is only 10 numbers, and the workload may be a little larger, but it is a very simple step.

What is your BCD code 8421? 5421？2421？。。

Compressed or uncompressed Compression is a little easier to handle.

Does your design use microprocessors such as microcontrollers?

If it's a separate logic circuit, it's more troublesome to convert it directly.

It would be much more convenient if it had a processor.

After the weighted binary, add it with an adder.

Truth table + Carnot diagram simplification?

4-bit binary code (0-15) to BCD code conversion circuit0-15 is wrong.

It's just a logic circuit, no chips.

Seeing that you love learning so much, I'd better tell you.

Let the three machines work as 1 and do not work as 0;

The normal operation of the machine tool is 1, and the abnormal operation is 0

Below is a truth table that satisfies the question.

a b c y

Only two units are allowed and must work, and b and c are not allowed to work at the same time, y=abc'+acb'

To be represented by the NAND gate, it can only be transformed into NAND - and NAND forms, and take the non-operation Y"=(abc'+ACB')" twice

（abc’）’acb’）’

Okay, here's the gate circuit**! I've been drawing for a long time, and I'm tired to death, hehe.

I want to give you the circuit, but I can't.

The M motor is connected in parallel with the light of the L refrigerator, because there are two current paths in the circuit after the switches are closed, or the two ends of M and L are connected together and then connected to the power supply.

Gross, it's too much trouble. It took me half a day to draw it, and it's in this book, so draw a Carlo diagram first, and then draw out each truth value) and then connect it.

Open the door and turn the lights on! c.When the refrigerator door is opened, the S1 is disconnected, and the light is connected in parallel with the motor, and the S1 disconnects the light and does not turn on? That must be C incorrect!

Your diagram won't open.

Is the s1 a light switch? If yes: aWhen the refrigerator door is closed, the S1 automatically disconnects.

S2: Is it a thermostat? If yes: bWhen the temperature in the refrigerator drops to the set temperature, the S2 switch is automatically disconnected.

Is the s1 a light switch? If yes: aWhen the refrigerator door is closed, the S1 automatically disconnects.

S2: Is it a thermostat? If yes: bWhen the temperature in the refrigerator drops to the set temperature, the S2 switch is automatically disconnected.

o(∩_o...Hehe.

What brand of refrigerator? Generally, there is only one single-door refrigerator.

Thermostat, and you're talking about a single-door refrigerator that's refrigerated or frozen? Double-door single-opening refrigerators generally have only one thermostat, if there are two, generally one is controlled refrigeration and one is controlled freezing.

The circuit of the refrigerator is a thermostat.

Circuit diagram posted on the back of the refrigerator.

That is, one temperature control and one compressor.

You can refer to the knowledge points in the book.

It's hard to get inside the computer.