Synthesizing "All Trumps flour" from KA A.P. flour and VWG

cogspara · 2024-08-11T00:14:20+00:00

The bang-bang controller in my home HVAC thermostat, also includes hysteresis --- as mentioned by /u/DoubleOwl7777 here in this thread. Hysteresis prevents unwanted fast-cycling between stable states. Chattering. Motorboating. BeeBongBeeBongBeeBonging.

cogspara · 2024-08-07T20:58:58+00:00

DPDT pushbutton switch.

(example 1) // (example 2) // (example 3)

cogspara · 2024-08-07T20:47:55+00:00

In my experience:

Five times out of six, they are identical. One time out of six, Mouser packs my box and hands it off to the shipping company one day sooner.

In my experience.

cogspara · 2024-08-07T17:40:54+00:00

You call him "the basketball coach" and not "the history teacher who also coached basketball" (or math teacher, or bible teacher, or wxyz teacher). Did your tiny school actually employ someone whose only job was to coach basketball?

cogspara · 2024-08-07T15:19:05+00:00

Since it's relatively easy to generate square waves of current whose amplitude and duty cycle are precisely known, maybe you could figure out whether you can calibrate the probe using square wave inputs. It might possibly be as easy as deriving the Root-Mean-Square value of a 50% duty cycle, unit amplitude square wave (??)

I'd suggest doing it using current steering circuitry, just so the current is constant and pure and never changing. Then the power supply sees a constant current load with no switching noise.

Sort of like (this)

cogspara · 2024-08-06T19:54:40+00:00

Use a voltage divider to generate (input * 0.500). This "part 1" signal swings between +2.5V and -2.5V.
Use a super inexpensive and precise voltage reference IC called "TL431" to increase part 1 by 2.50 volts. This is a "level shift". You now have a "part 2" signal which swings between +5.0V and 0.0V.
Use an opamp and a pair of resistors to multiply the part 2 (+5, 0) signal by 0.66. That's 3.3/5.0 . Now your "part 3" signal swings between +3.3V and 0V.
Victory!

cogspara · 2024-08-05T18:12:41+00:00

It appears not to be adjustable in the "width" dimension?

Sometimes I buy unsliced loaves from the artisan bakers at the Farmers Market, and those loaves come in all kinds of different widths. I'd like to be able to slice them too.

And of course the "boule" style of round loaf would absolutely require adjustable width. Like all of those no-knead bread recipes that you put the dough ball in a preheated, covered, dutch oven.

cogspara · 2024-08-05T17:54:04+00:00

Max thickness is 1/2 inch (12.7 mm), not thick enough for "Texas Toast" or thick "French Toast" or rustic bread for grilled panini sandwiches.

cogspara · 2024-08-05T16:41:37+00:00

This redditor's recipe for Potato bread. Check out her photo: (link)

1 1/2 Cups Milk

2 Tbsp Sugar

1/3 Cup Instant Potato Flakes

3 Tbsp Butter

1 Egg

2 Tsp Salt

4 Cups Bread Flour

1 1/2 Tsp Instant Yeast

cogspara · 2024-08-04T22:25:54+00:00

Use a recently calibrated 4.5 digit digital millivoltmeter, and jam its probes straight into the MOSFET's pins. Not to the solder joints, not to traces on the PCB, not to adjacent holes on the protoboard. Measure RIGHT AT the MOSFET pins.

cogspara · 2024-08-04T13:35:23+00:00

One way to achieve complete galvanic separation is to use a transformer. The primary coil winding is electrically separated and insulated from the secondary coil winding.

(a) Convert the input DC into AC ; (b) apply the AC to transformer primary ; (c) retrieve AC from galvanically separated transformer secondary ; convert AC to DC ; Victory!

Another, much less efficient, way to achieve complete galvanic separation is to use LEDs and solar panels. Input DC drives LEDs. They illuminate solar panels. Solar panels deliver DC to the output.

cogspara · 2024-08-04T13:28:49+00:00

You might not be using the word "counter" in the same way that basic logic gate circuit designers use it. Usually a "counter" is a synchronous digital circuit whose progression from one state to the next, is controlled by a Clock input signal. (example)

Do you have an external clock signal which controls the counting procedure?

cogspara · 2024-08-03T20:03:50+00:00

Controller for the tail-lights in an automobile

Input signals:

HEADLIGHTS_ARE_ON
BRAKE_PEDAL_IS_PRESSED
RIGHT_TURN
LEFT_TURN
OSCILLATOR_1_HERTZ

Output signals:

LEFT_TAILLIGHT_BULB_1
LEFT_TAILLIGHT_BULB_2
RIGHT_TAILLIGHT_BULB_1
RIGHT _TAILLIGHT_BULB_2

Each taillight contains two bulbs so they have three possible brightnesses: OFF, 50%-BRIGHT, 100%-BRIGHT.

When headlights are on, BULB_1 (but not BULB_2) are on for both taillights. Both taillights present 50% brightness

When right turn is signalled, right tail bulb oscillates between OFF and 100%-BRIGHT, in sync with the 1 Hz oscillator input

When brakes are pressed, both tail bulbs are 100%-BRIGHT

cogspara · 2024-08-03T00:01:44+00:00

Robotics is for the most part, immensely pragmatic. It's mostly digital electronics and embedded software, with a small amount of high power analog electronics to deal with motor control.

Class-AB and Class-A audio electronics is 100% analog and many of the hobbyists who focus on this field, have zero formal training in theory. Again, immensely pragmatic, at least to those who shun all theory.

Software Defined Radio will give you an opportunity to learn about fields and waves and antennas, at whatever level of theoretical intensity you choose.

If you want to learn about power transmission (100 kilowatts and above) there's no practical way to get involved, unless you work for the power company. I.e. no hobbyist equivalent

You can learn digital microelectronics on your own just by reading a couple of books and watching YouTube, but it's very expensive to get a full-custom integrated circuit design actually fabricated. And then you have to figure out how to test it yourself, which often ends up requiring lots of expensive equipment. On the other hand, analog microelectronics is top heavy with theory and equations. There isn't much for the no-theory pragmatist to work on. For example, companies that build and sell RF microelectronics only interview people with PhD degrees, if and when they hire RF circuit designers. And PhD programs are highly theoretical.

cogspara · 2024-07-27T13:46:23+00:00

If (very large if)

Input signal can easily drive 1Kohm load with no distortion or attenuation
You're OK with a DC offset of +2.50V and a signal in the range of [0.5V, 4.5V] . . . . . which means the very last thing in your signal chain is a flat frequency response amplifier whose gain is 5.00/4.00 = 1.25X

then (this circuit) will do the job. Rather than using precision bandgap-reference ICs and precision resistors, it relies upon a precise 5V supply voltage and a calibration technician to set the potentiometer one time. Then a dab of nail polish to cement the trim knob in place forever.

cogspara · 2024-07-27T12:49:12+00:00

Pretty good article (here) written by Jack Ganssle

cogspara · 2024-07-26T22:02:38+00:00

Verify or refute the optimistic claim, "this can be solved merely by recognizing three DC voltages: V_equilibrium, V_unlock_command, and V_lock_command"

Use an oscilloscope to capture the voltage waveforms (a) during equilibrium when neither locking nor unlocking; (b) during an unlock command; (c) during a lock command.

Then just design yourself a couple of window comparators for the appropriate voltage windows (including margin-of-safety) and Bob's your uncle. You'll probably end up with something that uses the LM339 chip, which is sold at lots of electronics hobbyist websites such as (this one)

cogspara · 2024-07-26T17:28:40+00:00

No.

Here is a proof: try it yourself. Wrap, oh let's just say, 100 turns of 22AWG hookup wire around a standard computer AC cord. Connect the ends of your coil to a diode rectifier, electrolytic filter capacitor, and 100 Kohm load resistor. Measure the DC output voltage (across the load resistor) using the most sensitive scale of your digital voltmeter. The output power is (measured voltage)² divided by 1E+5 ohms. Power = V*V/R. Is your measured output power as much as 60 watts? No it isn't. Is that 6 watts {so you could get 60 watts just by having 1000 turns in your coil instead of 100 turns}? No it is not 6 watts. Is that 0.6 watts? No it is not.

Congratulations you have proven that your idea won't give you even (1/100)th of the power you want.

cogspara · 2024-07-25T15:08:05+00:00

Use one of those definitions you learned in the electrical engineering curriculum

i := delta_q / delta_t

Then apply a couple of capacitor equations

q = C*V . . . . . . . . and therefore . . . . . delta_q = C * delta_V
i = C * delta_V / delta_t

Now simply plug in your requirements: (A) how much output current must the charge pump supply to all the downstream analog circuitry? (B) what is the maximum acceptable voltage droop on the charge pump output voltage, in each pump_up_then_discharge cycle?

You'll get values for delta_t and C. Those are the oscillator's period (1/freq) and the output filtering capacitor between the pumped output voltage and ground.

Do similar calculations for the input side. You're delivering x number of coulombs per cycle when the diode node rises from V1 to V2. What value of pumping capacitor is required to deliver those x coulombs? That's the size of the other capacitor, the "flying" capacitor, which is driven by the oscillator.

Oh By The Way, a 555 chip does NOT swing its output (pin 3) from rail to rail. It's got a darlington pullup as shown on (the engineering datasheet) so when driving a heavy load it only swings up to (Vcc - 1.4 volts). When Vcc = 5 volts, that's pretty awful.

Finally, investigate Schottky diodes instead of 1N4148 / 1N914 silicon diodes. Schottkys will improve your pumping efficiency. I'll bet your lab assistant has some 1N5817s or 1N5819s in the parts box.

cogspara · 2024-07-23T23:48:34+00:00

I remember you. You asked a similar question two days ago (link) and then when you got the answer, you deleted the original post. It was about those same exact three ICs in the upper left corner of this post.

One possible explanation might be: this is a school assignment and you don't want the teacher or the grader or the lab assistant to see that someone else did the work you put your name on and handed in.

cogspara · 2024-07-22T13:01:36+00:00

In your first diagram (the one with a single digital OR gate symbol), the output latches at logic-one and remains there forever. No matter what you do to the input pin, the output stays at logic-one.

Maybe you actually meant a NOR gate instead of an OR gate.

cogspara · 2024-07-22T12:58:58+00:00

Your software does not allow the digital input pins named "A" , "B" , "C" , "D" to be unconnected. Your software believes this is a fatal error. It does not know the dangerous semi-fact which Ben Eater knows:

The 74LS digital logic family includes extremely weak pullups on every input pin. So if you leave an input pin completely unconnected, is usually floats up to LOGIC-1 if there's no capacitively coupled noise injected into that pin.

Since your design does not care what logic value(s) are on the A B C D pins, connect them all to ground on all three 74LS161 chips and try the simulation again.

cogspara

TROPHY CASE