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# HarryA

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1. ## Win 30,000\$ helping NASA

Help NASA explore the moon and win up to 30,000\$. See: https://www.herox.com/crowdsourcing-projects/government
2. ## 555 push pbutton

Two things from your circuit are the 20k ohm potentiometer and the 10k resistor at pin 2. The potentiometer going from 0 to 20k ohms can produce a wide range of outputs in time/widths. So the RC circuit must charge above 4 volts fairly fast to accommodate the shortest output and while charging through the 10k resistor. A 1.0 ufd would require 20 ms, perhaps to slow. So trying a 0.1 ufd gives 400 microsecond which would seems fast enough(?). To discharge the capacitor before the next switch closure the parallel resistor must set the voltage at pin 2 above the required 4 volts while the switch is closed. A 50k sets the the voltage at: 50K/(50k+10K) * 12volts or 10 volts a bit higher then necessary. A 10k resistor would set the voltage at 10k/(10k+10K) * 12 volts or 6 volts which would be adequate. Discharging from 6 volts to 4 volts in 2 ms after the switch is opened.
3. ## 555 push pbutton

What you want to know is will the capacitor charge to above 1/3 of Vcc within the period of the 555 pulse; thus it will not get re-fired. Using: You get 405 microseconds, See: http://mustcalculate.com/electronics/capacitorchargeanddischarge.php And will discharge to 4 volts from 12 volts through the 50k resistor in 5.6milliseconds.
4. ## 555 push pbutton

I am lazy and use one of the numerous online calculators like: http://referencedesigner.com/rfcal/cal_05.php
5. ## 555 push pbutton

In the photo the yellow trace is pin 2 (trigger) and the blue trace is pin 3 (output). Starting on the left pin 2 is at the Vcc voltage of 12 volts (0 is at the bottom of the screen) . Pin 3 is at 0 volts. On switch closure pin 2 drops to near 0. And pin 3 rises to near 12 volts. The switch is held on until the later part of the trace on the right most side of the screen.
6. ## 555 push pbutton

Try putting a resistor and capacitor in parallel after the switch. The capacitor will pull pin 2 down until it charges through the upper 10k resistor. The resistor in parallel with the capacitor will discharge the capacitor during the period the switch is open. Do you need help with the calculations? As a quick test make the new resistor 50k and the capacitor perhaps 0.1ufd - I am just guessing. You want the capacitor to discharge before the output ends.
7. ## RF Wireless Charging Technology

It is interesting to look at their patents: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=0&f=S&l=50&TERM1=Energous+Corporation&FIELD1=AANM&co1=AND&TERM2=&FIELD2=&d=PTXT
8. ## RF Wireless Charging Technology

Over the air wireless charging transmitter. Nikola Tesla would be proud of them. see: https://www.energous.com/company/about-energous/ Energous stock traded at a volume of 123,210,608 shares today; the average trade per day is 671,390. Symbol is : watt
9. ## Design real time temperature monitoring

I do not know the PIC micro-controller so I can not help you directly. But there are videos on youtube that maybe helpful. for example: https://www.youtube.com/watch?v=yreD5sj-i80 Also for the basic calculations see: https://www.instructables.com/id/NTC-Temperature-Sensor-With-Arduino/ Good luck with your project.
10. ## 5S3P Series parallel reverse polarity protection ?

Yes, you would want the diode across the cell not in series thus they would only conduct on reversed voltage. Your cells are connected in parallel due to the interconnectors thus I see no way to monitor the voltage of individual cells.
11. ## 5S3P Series parallel reverse polarity protection ?

Are the leads from R13, R14, & R15 shorted by the interconnections between B10, B11, & B12 ? As the fuses interconnect them. I do not understand why, in say laptop batteries, the cells are interconnected that way. Perhaps for balance charging? It is common practice to put a diode around each cell in reverse connection for protection.
12. ## External Telephone bell as an alarm

You can get a 120 volt to 48 volt transformer for about 15\$ off Ebay. That still leaves you with 60 hertz which would be expensive to converter down in frequency. Perhaps 60 hertz would work? I used a pocket am/fm radio for a signal device; just opened the lead to the battery for external connections. You can get one for 10\$.
13. ## 5S3P Series parallel reverse polarity protection ?

See "PCB Protection Board For 18650 Li-ion Lithium Battery Cell " https://www.ebay.com/itm/2S-3S-4S-6S-BMS-PCB-Protection-Board-For-18650-Li-ion-Lithium-Battery-Cell-US/283479999258?ssPageName=STRK%3AMEBIDX%3AIT&var=584554774361&_trksid=p2057872.m2749.l2649 Also see "Build a 2S Li-ion Battery Pack with Protection" https://www.youtube.com/watch?v=VwIYAiDlMz4
14. ## 5S3P Series parallel reverse polarity protection ?

Do you need reverse polarity protection only when in use? As I take the batteries out of my camera to charge them. Only when you are charging the batteries? Or both?
15. ## Amplifier based on mosfet

What type? Voltage Amplifiers: Power Amplifiers: Class A, B, AB, & C Audio Frequency Amplifiers (A.F. Amplifiers): Intermediate Frequency Amplifiers (I.F. Amplifiers): Radio Frequency Amplifiers (R.F. Amplifiers): Direct Coupled Amplifiers (DC Amplifiers): Ultrasonic Amplifiers: Wideband Amplifiers: Video Amplifiers: Buffer Amplifiers: Operational Amplifiers:
16. ## String lights in resin lamp

If you could make a slight indentation or groove at the wires with a Dremel like power tool perhaps you could fill it with conductive epoxy? Silver based epoxy is best but expensive. For insight into conductive epoxies see: https://www.permabond.com/2016/07/26/electrically-conductive-adhesives/

There are dc electronic dummy loads reviewed on youtube.com if that is helpful. They run 200v, 20A, and 180watts. For example see: https://www.youtube.com/watch?v=bx74sNFQvwc
18. ## In the bowels of: Sonic Sensor

An experimental blind spot monitoring (BSM) for an automobile. One can attach the sonic sensor on the rear section of the automobile. I mounted mine on the flap door that covers the gasoline cap. I used a length of good duct tape that wrap around the inside of the flap door also. I ran a length of 4 wire telephone cable from the sensor through the backdoor gap into the backseat. Then a length of 2 conductor wire from the Arduino Uno to the dash for a white LED. The LED has an 68 ohm resistor in series with it. The LED and resistor lives in the plastic tube For the Arduino Unio one can control the LED blinking without using the Delay() by: int iLEDstate = LOW; // used to set the LED state const long lInterval = 1000; // interval at which to blink (milliseconds) unsigned long lPreviousMillis = 0; // will store last time LED was updated int iDashLED = 10; // LED on/off pin pinMode(iDashLED, OUTPUT); //only distances more than 3 ft and less than 12 ft if(lInches > 36 && lInches < 144 ) { Dash_LED_Blink(); //blink the LED } else if (iLEDstate == HIGH) { iLEDstate == LOW; digitalWrite(iDashLED, iLEDstate); //make sure LED is off } void Dash_LED_Blink() { // check to see if it's time to blink the LED unsigned long lCurrentMillis = millis(); if (lCurrentMillis - lPreviousMillis >= lInterval) { // save the last time the LED blinked lPreviousMillis = lCurrentMillis; // if the LED is off turn it on and vice-versa if (iLEDstate == LOW) { iLEDstate = HIGH; } else { iLEDstate = LOW; } // set the LED with the iLEDstate digitalWrite(iDashLED, iLEDstate); } }
19. ## In the bowels of: Sonic Sensor

In the photography is the "Ultrasonic HC-SR04 distance measuring transducer sensor". "HC-SR04 consists of ultrasonic transmitter, receiver, and control circuit. When triggered it sends out a series of 40KHz ultrasonic pulses and receives echo from an object. Power supply: 5V DC; quiescent current: less than 2mA; effectual angle: less than 15°; distance: 2cm - 500cm." The sensor is 1.75 inches/ 4.45 cm by 0.75 inches/ 1.9 cm. The IC on the bottom left is an LM324 quad op amp. The two on the right are not marked. // The sensor is triggered by a HIGH pulse of 10 or more microseconds. Give a short LOW pulse beforehand to ensure a clean HIGH pulse: digitalWrite(iTrigPin, LOW); //pin 12 Out delayMicroseconds(5); digitalWrite(iTrigPin, HIGH); delayMicroseconds(12); digitalWrite(iTrigPin, LOW); // Read the signal from the sensor: a HIGH pulse whose duration is the time (in microseconds) from the sending of the ping to the reception of its echo off of an object. pinMode(iEchoPin, INPUT); //pin 13 In lDuration = pulseIn(iEchoPin, HIGH); The photography shows the trigger pulse in blue and the signal from the sensor in yellow bracketed by the white cursors. In the lower right is the width of the pulse: 24.4 ms from a object at 16 inches/ 40.6 cm from the sensor. // Convert the time into a distance - long way for clarity lCM = (lDuration/2) / 29.1; // Divide by 29.1 or multiply by 0.0343 lInches = (lDuration/2) / 74; // Divide by 74 or multiply by 0.0135 So for 2440 us/2 = 1220/74 = 16.48 inches or 1220/29.1 = 41.9 cm
20. ## LED Voltage

White LEDs are typically 3.6 volts and 20ma each. So for the 6 LEDs you would need in the order of 21.6 volts and 20ma. You could try two 9 volt batteries as a test. You can connect two batteries head to head with the + to - connectors. For insight on testing LED strips with batteries see; https://www.youtube.com/watch?v=4pK6o2DMLWQ
21. ## Burnt Resistor

Also see: https://www.fixya.com/support/t8108170-click_multi_functional_rechargeable for more discussions on the rechargeable torch..
22. ## DARKROOM TIMER V2.0A FOR PCB EXPOSURE BOX

Can you connect a 240v buzzer to the relay and get what you need? I don't know the circuit so I can not help much. Perhaps someone more knowledgeable will come along. I would think that the lead from the mains/transformer to the relay would be from the lead that has the fuse and power switch on it. The URL is here: https://www.electronics-lab.com/project/darkroom-timer-v2-0a-for-pcb-exposure-box/ What does this circuit do that a 60 minute egg timer could not do?
23. ## How is my schematic layout and design

The LEDs flash alternating. The flash rate is determined by C1 and R4. There are online calculators for determining these values. Just supply power for the hazard signals. Supplying power and disabling one or the other LED for the turn signal. Redraw the circuit with circuitlab and add a DPDT switch with center off perhaps for the turn signal.
24. ## How is my schematic layout and design

You should draw the fuse F1 as a blown fuse, you have a short circuit by the wire/conductor on the right. That was a test right? To see if anyone really looked at it 😉 Isn't the 7805 a voltage regulator? Not a flasher? What are the" flashers" connected to? Shouldn't they connect to the anode leads of the LEDs rather then the LEDs connecting to the Low Beam Terminal? What happens when the left and right flashers and the hazard flashers are on at the same time? Maybe okay. Could the DPDT switch be replaced with a SPST switch? Also on your SPDT there is no off position. Otherwise the schematic looks better than my poorly hand drawn schematics.

In my latest post  can you move the top photo up and remove the two redundant ones? I can not find a way to do it.

1. Can you check now? Is it correct?

2. fine

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