Cool projects to do

You can find lots of interesting projects on www.instructables.com, many of which are beginner-level. You'll even find some content there from me! (same username)

throbscottle said:

A J-K flip flop is like an S-R flip-flop but it has some extra gates built in which force it to avoid illegal conditions.

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And what is an SR flip flop?

A flip flop is basically a latch logic gate. Apply a pulse to the S(set) input, and the output will be latched on, regardless of what happens with the input to the S input.

Apply a pulse to R(reset) and the output will be latched off.

Flip Flop Basics

A JK flip flop is one of the variants of clocked or synchronous style bistable.

An SR bistable (aka flip flop) in not synchronous, it switches state as soon as either a set or reset signal is present.

The simplest clocked one is a D type; the output (Q) is set to match the D (Data) input only when the clock input changes from low to high.
Connect the inverse output /Q (not Q) to teh D and it will change state each time the clock changes to high, dividing the clock frequency by two.
Connect two or more Q out to D in, and clock them together, you get a shift register.

A JK bistable has two control inputs and extra logic included. If both are low, nothing happens when it is clocked. If J is high and K is low, Q is set high when the clock occurs; J low and K high, Q is set low when clocked. Connect Q to J and /Q to K and again you get a shift register.

Set both J and K high, and it alternates (divide by two) at each clock.

Most D or JK etc. type have reset and often set inputs as well, that force an immediate state change, like SR.
Those are most often used as part of a power-on-reset sequence so everything starts in a defined state, but can be used in other ways.

This video may be helpful:

Huh, I didn't think J-K had a clock input. Learn something every day.
Daniel, you can make a S-R flip-flop (the simplest kind) by connecting two of the gates in a 74HC00 together. 1 input from each gate gives you the S and R inputs, the outputs form the Q and not-Q outputs, you just wire the output of each one to the remaining input of the other one to make it into a flip-flop.

I think the point is being missed here. A flip flop has plenty of applications. There's been a lot of explaining about different types of flip flops, without any explanation of the why.

Flip flops are handy if you need one, but a flip flop on its own isn't a cool project.

Not cool I agree, but it's an experiment to try. I can still remember the magic of doing exactly that one myself many years ago. Even though I'd read it's truth table and explanation and thought I knew what to expect, it was still magic.

Is your solar charge controller the infamous Micro M+? I never sourced it or built it, but I plan to build it for use with my auto battery collection, using free energy from the sun.

shokjok said:

Is your solar charge controller the infamous Micro M+? I never sourced it or built it, but I plan to build it for use with my auto battery collection, using free energy from the sun.

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don't think its infamous

Wrong choice of the word infamous. Perhaps historic, vintage or ancient.

Ola ... Hmmm how to explain ... A flip flop is a type of temporary memory storage IC ... There are 3 common types: D, SR, JK ... The outputs of these devices can change states depending on what you set on the input and how the device is clocked (please search "<insert flip flop name> truth table" on the web to see what I'm trying to say) ... They can either be negatively or positively clocked ... Negative clock signal = signal that goes from on to off and positive clock signal = signal that goes from off to on ... 555 timer will come in handy for clocking signal because it eliminates something called bouncing when using mechanical switches or pushbuttons ... I found a great book on the web called "Digital Fundamentals" by Thomas L. Floyd ... It will explain it in a much better way so please try to download it ... Attached below is an application of a D Type FLip Flop to form a serial in serial out shift register that I had to do for school. YouTube Channel "Ben Eater" has the best tutorials on digital systems so check him out as well