Why does the transistor does not allow my LED to get brighter when the collector is connected to 9V source power?That's your problem - the collector is connected to the power source - you are using it as an emitter follower - the brightness will be totally governed by the base voltage from the arduino. Try operating it as common emitter with a 4k7 base resistor: -R1 330R or possibly a bit less to produce desired current thru LEDR2 - try 4k7
------2. Illuminating the wall of a transparent tube
You are asking about Edge lighting or Edge Lit. As a tube, it just means you have to make/fabricate a round ring of lighting. See How to make whole top side of project box glow uniformly? for a good primer on lighting plexiglas or acrylic sheets, everything applies. Including that the sides will not be highly lit, if they are smooth/clear. It would look like this, unless you go with opaque tube (meaning you won't see whatever is inside the tube):
------3. Potentially unusual LED failure
It seems that circuit is originally just meant for a neon bulb, and the manufacturer has simply replaced the neon bulb with a LED.In that circuit, there is no protection for the LED from reverse voltage being applied over it. LEDs typically have a reverse voltage limit of 5V.
So it will work with AC circuit like that for some time, but the LED degrades faster than in a proper circuit where the reverse voltage is prevented with another LED or diode
------4. Reflect IR beam off reflector instead of emitting straight to TSOP receiver
Yes, it is very possible. You just need to arrange the LED and detector appropriately.IR is just light that your eyes can't see. If you were trying to do this with a visible LED, what could you do?For example: You could put the LED inside an opaque box with a hole at one end, you could make it more of a "pinpoint" type of light. You could put the LED and detector next to each other with a wall between them
------5. ESP8266 module cutting connection with PC via USB
At which pins you connected the ESP8266?
The pins pin 0 (RX) an 1 (TX) are connectet internaly to the FTDI USB-to-TTL Serial chip.
If you using Serial.begin() to communicate with the ESP8266, you can't communicate with the pc at the same time.
Use SoftwareSerial to communicate with the ESP8266 an Serial to PC.It is also recommed to feed the ESP8266 with an external 3.3V power supply and stabilize with an capacitor. This could produces the sounds of ejecting and inserting a USB.
------6. Help with P-channel mosfets
You have the P-MOSFET connected wrong. The Source (S) terminal should be toward the 5V and the Drain (D) should connect to the LED in your diagram.The condition where the P-MOSFET will be off is if the voltage between the Gate (G) and the Source (S) is less than the VGSTHR.The reason that the LED lit up in your drawn configuration is because the body diode was forward biased and letting current pass from the D terminal to the S terminal.
------7. Unplugging power cord and holding the power button. PC won't turn on
It could be that your power supply died when you unplugged it (not saying it was because you pulled the cord but it also could be because of that). Try testing the power supply in the computer to make sure it works. If it fails the test then you need a new power supply.
Go to howtogeek.
com/172933/how-can-i-test-my-computers-power-supply/ to find how to test the power supply if you are hardware savvy or take it to somebody that can help you
------8. Trying to understand this schematic
Is there any benefit to separately buffering a common pin for each output?It's a best practice for daughter cards to buffer all input signals, and thereby isolate the "original" input signal from the "working" signal that's used by the components on the daughter card.Imagine having multiple daughter cards stacked onto each other, and each card tries to use the original signal. Connecting more and more digital loads to the same signal path can easily overwhelm the signal source's maximum fan-out specification.
------9. SSH Connection refused / SSH disabled?
Connection refused in combination with port 22 not showing up in a port scan generally means that SSH is not enabled on the system. Reinstalling SSH probably won't help you, but you could try to re-enable it.If you don't want to connect a screen, you can power down the pi, take the SD card out and mount in on a pc, put a file called ssh in the /boot directory and put it back in your Pi. This should enable the SSH server.
------10. Vs1838B break beam problem
IR receiver modules like you have typically reject continous 38kHz signal. You need to send for example a 500 microsecond burst of 38 kHz signal and then pause for some time - optimum value depends on how the AGC is tuned to allow optimum reception of certain kinds of common IR remote protocols. The datasheet of your module says it is tested with a signal of 600 microseconds of 38 kHz burst following a 900 microsecond pause, so it is a reasonable starting point for transmitting your signal.
------11. Mosfet controlled LED strip not bright enough
Based on you mentioning noise, I'm assuming you are using a PWM control scheme of some sort? Are you sure you are driving the devices on 100% duty cycle. Also if you are switching with PWM, you may need a dedicated mosfet driver, the IO pin on your micro controller is not ideal for driving mosfets with a PWM like frequency. The gate acts like a capacitor that is charged and discharged. Doing this quickly requires more then the 20mA drive of most microcontrollers
------12. What is the technical term for this style lighting?
example hereUsually the light source is hidden by an archtectural feature, so the feature is constructed by normal building means and then the light source is hidden in it. At my house we have one strip light hidden in an open topped curtain pelmet and another hidden behind an one of the exposed rafters.These are 5' flourescent tubes with 40 year old iron ballasts.Led strips could be hidden in a cornice moulding. etc.it's going to be tricky to clean.
------13. How can I use Charlieplexing with common anode RGB LEDs?
In the following figure, the LED array consists of three common anode LEDs connected together.The PWM signal created by the controller is amplified by a transistor prior to being applied to the array. The amplitude of 5V is too low to drive the array directly. If the array size is increased, additional paths must be connected to the multiplexer and additional transistors may possibly be required for amplification. This circuit is from an OSRAM App Note: Driving LEDs with a PIC Microcontroller
------14. Can I connect a single color LED string to a RGB DMX512 controller? closed
This was posted a long time ago but was never really answered.But to answer; Yes! this will work just fine. The LED doesn't care what kind of signal it receives because all it wants is power. Which is exactly what your DMX RGB bridge provides. It literally "bridges" the digital DMX signal and converts it into an analog RGB signal. Technically, it converts it into just an analog power signal, but in this case, the bridge has the outputs marked RGB. Handy.
------15. Max bulb wattage for a lamp
The construction and insulation of the socket assembly, the size and temperature rating of the wiring, the proximity and design of the shade... generally anything related to either electrical current or heat affects its wattage rating. Using a bulb of higher wattage than the lamp is rated for means that wiring may be overloaded, causing it to heat up, and/or the structure of the lamp will heat up due to conduction and radiation from the bulb. Either can cause burns or fires.
------16. Can I install a photocell on a 3-way switched circuit?
What I have noticed is the three way doesn't necessarily control the lights meaning when it is dark the switches are hot but when you turn them off or on the light will stay on but if you have the switch in the middle neither off or on the light will be controlled by the switch. I ended up taking out the photocell since we have lightning restrictions so I put in a timer switch so the lights wouldn't be on till dawn
------17. Connecting LED to RO pin of RS485 Transceiver
If the baud rate is above a few hundred hertz, the LED flashing will be indiscernible to the human eye - it will merely appear dimmer.It's usually better to buffer the signal with an opamp, then use the buffered signal for 'other' purposes (like driving an LED) so that whatever else is connected to the receive line isn't influenced by the current drawn by the LED (I/O usually isn't stiff).Again, unless you're operating e-x-t-r-e-m-e-l-y s-l-o-w-l-y you won't see any flashing.
------18. Trying to set up wireless router, failing
Reset your router (and this will reset the default gateway back to 192.168.1.1). Then reset your modem. Power down everything and start from scratch. Reboot your computer as well.Re-establish network connectivity and the ability to connect to the outside world and the internet.
You may want to turn off all your firewall tools (and maybe AV software too) while troubleshooting this process.Do you have another computer you can add to the mix for pinging, like a laptop? This sometimes helps with troubleshooting
------19. Optical measurement of CO2 with LED
It turns out there was a mistake in the teardown. The "optical CO2 sensor" is in fact an RGB LED. The outdoor weather station does not measure CO2 at all. The 5% accurate CO2 sensor mentioned in the Netatmo documentation is this chunky module in the internal weather station:
I reached out to Fictiv and they said they would update the teardown. I guess the lesson is, if something sounds too good to be true (eg measuring CO2 with an LED), it probably is!
------20. Control Output Shock From Cockroft-Walton Doubler
There is, as I understand the question, a fairly simple solution.simulate this circuit Schematic created using CircuitLabOf course there is a slight problem - what sort of relay will hold off kilovolts?Ah. Well, it's called a vacuum relay. For an array of surplus vacuum relays, see here. Depending on how much you're willing to spend, you can easily handle 10 kV and 50 amps of discharge current.They are physically big and way expensive, but you didn't say that would be a problem
------21. Is white a single color? duplicate
It is simple :Newton demonstrated that white light could be broken up into its composite colors by passing it through a prism, then using a second prism to reassemble them. He also discovered that sunlight is composed of light with wavelengths across the visible spectrum. Concluding that since all colors produce white light then white must be made up of all colors is a common logical error called affirming the consequent, which might be the cause of the misunderstanding.Source : WikipediaSee picture below :
------22. How to set up WiFi with Raspbian wheezy
Both those approaches you've linked are WPA based. If your network really is WEP, it's a slightly different process. Try editing the /etc/wpa_supplicant/wpa_supplicant.
conf file and adding something like this:If that doesn't work you can try configuring it manually from the command line with the iwconfig utility:Drop the "s:" if your WEP key is a hexadecimal code rather than a string password. (In the wpa_supplicant example use "" for a password and without for a hexadecimal code.)
------23. Connecting SSR module to raspberry pi or arduino (HCMODU0115) closed
Here is the easiest way to make this work- add just one part (per output):simulate this circuit Schematic created using CircuitLabThe internal schematic of the module is something like this (from here):The Omron SSR gets about 0.7 or 0.8V less than the supply voltage, and it needs 4V minimum to work reliably so it really needs a 5V supply. It starts to turn on a couple diode drops below the supply so more than the maximum output voltage of the 3.
------24. How to improve my curve fitting for an LED in spice
I assume that the blue curve is your actual LED device and orange is trying to predict its characteristic. The blue device is clearly an LED in series with a resistor so your model needs to be put in series with the model of a resistor.Here's a picture of the forward characteristic of an LED with resistance added in series: -As you can see, adding the resistor linearises the response above the basic point where forward conduction begins. Picture stolen from here.
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