Questions tagged [pnp]
A type of bipolar transistor comprised of p-type semiconductor in contact with n-type semiconductor which in turn is in contact with a p-type semiconductor -> thus PNP. The transistor has three terminals, the Emitter, Base and the Collector. Current injected into the base controls the flow of current from Emitter to Collector enabling amplification and switching.
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Art of electronics - figure 2.10 [duplicate]
Why shouldn't the resistance of R3 be less than 100 ohms? (See note 12 mentioned at the bottom of the image.)
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Is this PNP transistor pair a comparator or a special differential pair?
I am trying to understand this circuit, specifically the PNP transistor pair Q8 and Q6 on the right side.
The full circuit is supposed to demodulate a 40V signal that sends a few impulses around 29V.
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Interchanging/swapped Emitter and Collector of a NPN BJT - detection by measuring its diodes, but why BC diode has lower voltage
Measurements with Swapped Emitter and Collector
I wanted to measure 6 pieces of a BC547C (npn BJT) Q1...6 that each drives a relay (24 V, 75% on, 2.88 kOhm) powered by an old notebook SMPS of 19.5 V ...
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From NPN to PNP: What’s Different in Base Control?
I’m having trouble understanding the basics of the second transistor schematic (the PNP circuit). My professor said I need to get familiar with how to control a bipolar transistor in an ideal setup.
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user591323
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Problem understanding a voltage controlled current source (opamp + npn)
I will try to summarize my problem the best I can.
I have a circuit I use to generate a voltage pulse. This circuit consists on a voltage-controlled current source with a 54.9ohm shunt resistor, a PNP ...
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ESP32 control GREEN LED in LOW state and RED LED when HIGH state
I want to control two LEDs (red and green). The circuit is powered by 5V DC. The green LED is active 3.2V/20mA when the ESP32 pin is LOW (0V). When the pin is HIGH (3.3V), the green LED is inactive ...
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Optimizing Short Circuit Detection Circuit for Temperature Range and Voltage Thresholds
Problem:
How can the attached circuit be optimized so that, over a temperature range of -50°C to 150°C, the short circuit detection threshold lies between 5 V and 9 V?
Requirements:
The circuit is ...
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Selection of heatsink and/or decreasing power
A few months back I asked a question about how to implement a voltage regulator to reduce the given rectified 33V supply voltage to about 24V. I decided to use the LM78S24 paired with a BD536 (both ...
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Identify 3-pin SMD component with marking “K38” (not a BSS138)
I’m investigating some intermittent failure on a key fob. On the circuit, I found a 3-pin SMD component that I haven’t been able to identify. As far as I can tell, the package looks like SOT-23. I can ...
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What might be wrong with my very simple low voltage disconnect (LVD) circuit?
I have a device that produces 12VDC from a lithium battery. When battery goes low, it doesn't cut power and still produces voltages below the designated output. As a low voltage disconnect circuit on ...
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The PNP transistor as a switch from a single source in the Proteus
I try to decrease the voltage on the base using the R1 for turning on the PNP transistor in forward bias mode (while V(Emitter) > V(Base) > V(Collector)). But adding of the R1 hasn't any effect....
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Voltage Unit in Transistor Datasheet
I was referring to this datasheet of SS8550 PNP transistor. In page 3, under "TYPICAL PERFORMANCE CHARACTERISTICS" section, there is a graph of Base−Emitter Saturation Voltage and
Collector−...
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PNP Base Resistor Value Question
Attached is the circuit I have as well as the datasheet for the BJT. The premise of the circuit is to have the PNP act as a switch for a light with a 1A max current. Typically, using no more than ...
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How does transistor T1 work in this relaxtion oscillator circuit?
I’m new to this topic, so I apologize if my question sounds dumb.
I cannot understand how transistor T1 enters its active/saturation state in this configuration. As soon as the circuit is powered, ...
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Purpose of the Resistor in the Relay Module
I bought a 30A relay module for one of my projects. The image of the module is given below.
https://robocraze.com/products/single-channel-12v-relay-module-30amp
The schematic diagram of the module is ...