Date 8/30/06 Simon and delabs Simon: hello, delabs: hello
Simon: we have many meanings for saturation, delabs: means turning on, also means no longer linear, or it is got fixed up, not varying in accordance to any formula
Simon: that is what is concluded of. but we just wanted to be sure. delabs: like you put salt in water. after some time no more salt can be dissolved, that is the state of saturation, In Electrical, no more relationship with V - I - R. Any increase in voltage or reduction it is same
Simon: thanks delabs: anytime
Bipolar transistors are so named because their operation involves both electrons and holes. These two kinds of charge carriers are characteristic of the two kinds of doped semiconductor material; electrons are majority charge carriers in n-type semiconductors,
This concludes this episode of Saturated Talk with Simple Simon. Next week, a new Episode which will cover effects of Lightning Bolts.
Transistor Operation - A transistor in a circuit will be in one of three conditions. Cut off (no collector current), useful for switch operation.In the active region (some collector current, more than a few tenths of a volt above the emitter), useful for amplifier applications.
"Saturation also implies that a large amount of minority carrier charge is accumulated in the base region. As a transistor is switched from saturation to cut-off, this charge initially remains in the base and a collector current will remain until this charge is removed by recombination."
The following was submitted on July 11th, 2007. Message: I want to combine Ne555 with 74154 IC.The indication of the outputs must be shown with LED's but up to so far it need 15 outputs ,is it possible the way i did? if not i will need your assistance
Mail from CY
LED running lights are used to decorate Christmas Trees, Festival Surroundings and even Buildings. A Clock and a counter are basically required. Many LEDs can be used in parallel with driver transistors. Upto 15 count is is good enough. Many colors can be used and with a PWM or VCO you can make it Audio or Music effects lights like strobe lights.
Multi-Colored LEDs and drivers and even PIC microelectronics with Visual Effects in the form of ROM tables can make Alphabets and Numbers appear in LED arrays. Some have made Mini Ocillosocpes and Toy Spectrum Analyzers too in LED DOT Matrix Arrays. LED Sequencer Circuit
The above circuit is another variation of a basic LED sequencer circuit. Note again the use of the 555 as a clock. The 555 is likely one of the most versatile chips ever invented. The output of the 555 is coupled to a 4017 Decade Counter Divider another very widely used chip
555 and CD4017 Running Lights
The 555 clocks 4017 counter and it counts and Ten LEDs indicate the counts. This can be used as a Sequential timer or for generating staircase waveform.
I am a University Physics technical staff member and I am searching a Diagram and full detals about Ultra sound detecter (Sender & receiver & Detecter). It must be arround (Detecting range ) 1.2 MHz. This is for the student practical activities.
Pl help me if you have any information. This will be a gratefull help to the students for their studings.
"Sounds in the range 20-100kHz are commonly used for communication and navigation by bats, dolphins, and some other species. Much higher frequencies, in the range 1-20 MHz, are used for medical ultrasound."
Silicon Chip Online - Circuit Notebook - Besides being used as a Bat Detector, the circuit could also be used as a simple tool to indicate frequency, to find tyre punctures (which emit ultrasound), ...
The max power dissipation of my circuit is 20.5V x 0.5A = 10.25W, but transistors I found are 2W power dissipation. But my input voltages is just varied from 18.0V to 20.5V only. Do you think the 2W power dissipation transistor is fine? Any help will be appreciated.
Mail From MT
When the Current source output is short circuited or connected to a low impedance load say 10 ohms, the full voltage of input 20V falls across the transistor but current is limited to 0.5A. which means the 2W transistor may Roast. The transistor when conducting, the watts is the volts across it and current thru it. Not your supply Voltage.
Design in such a way there is no short circuit or a a power resistor in source. But then efficiency drops. The best way is to use a switching supply design or keep the input voltage across transistor to a minimum.
HELLO THERE ...COULD anybody pls help me with a place to get more information on the following components...cant seem to find it anywhere.
W20NB50 W8NB100 found them in a liteon power supply pack for a database supply. i just don't know what they stand for. ...saw on a web page that it is produced by ST micro electronics. i went there but no show ..can somebody pls help?
post by FP
W20NB50 ST Power MOSFET Transistors TO-247 N-Ch 500 Volt 20 Amp
W8NB100 ST Power MOSFET Transistors TO-247 N-Ch 1000 Volt 8 Amp
"The source-to-body and drain-to-body junctions are the object of much attention because of three major factors: their design affects the current-voltage (I-V) characteristics of the device, lowering output resistance, and also the speed of the device through the loading effect of the junction capacitances, and finally, the component of stand-by power dissipation due to junction leakage."