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    [SOLVED] Help identify component

    Hi Edaboard I have four components on a PCB controlling a Pneumatic valve Two of them have text according the picture The other too look the same but with the text (my interpretation) Top row: SU4 or S U4 Mid row: 355 Bot row: Same except letter C Best regards Peter
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    Fluke specification question DCV

    Hi! I have a FLUKE 85 III True RMS Multimeter. With the following DCV specification "Accuracy ... ± ([% of reading] + [number of least significant digits]) For model 87 in the 4½-digit mode, multiply the number of least significant digits (counts) by 10." "Display: Digital: 4000 counts...
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    JFET I-V questions, SedraSmith

    Hi! I have the following problem "The figure a) shows the circuit symbol of a device known as the p-channel junction field-effect transistor (JFET). As indicated, the JFET has three terminals. When the gate terminal G is connected to the source terminal S, the two-terminal device shown in b) is...
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    Source-absorption theorem

    Evening! I'm looking at an example (see figure 1). They want to know an expression of Rin. Solution: "From the figure we see that the voltage vΠ will be equal to -ve. Thus looking between E and ground we see a resistance rΠ in parallel with a current source drawing a current gmve away from...
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    [SOLVED] Simplified BJT model question (sedra smith)

    Thanks! I tried a some of the other methods without success but the superposition worked! Thanks!
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    [SOLVED] Simplified BJT model question (sedra smith)

    Ahh okay, but how do I incorporate that into the Ve-equation? I've been looking around at different methods (DC network analysis methods) but I can't get anyone to work. Could you point me in the right direction?
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    [SOLVED] Simplified BJT model question (sedra smith)

    Hello! Another question regarding a problem in Microelectronic circuits 5th ed by Sedra Smith (exercise 1.20) Please see the attached image. Everything except the green arrow and label is in the original figure Problem: Find the input resistance between terminals B and G in the circuit shown...
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    Voltage amplifier model (excercise question from Sedra Smith 5th ed.)

    Thank you for the answer, two questions. 1. Do you use the fact that Avo = "Open-circuit voltage gain" so RL is assumed infinity i.e. Avo = Av = 100 V/V (or 40dB)? 2. Can you explain why my answer to question #2 is incorrect? Power gain = Pout / Pin Pout = Vout^2 / RL Pin = Vin^2 / Ri same...
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    Voltage amplifier model (excercise question from Sedra Smith 5th ed.)

    So you agree with solution 1? Is the power gain calculation correct? In that equation I use the input resistance.
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    Voltage amplifier model (excercise question from Sedra Smith 5th ed.)

    Hi! I'm doing some exercises in Microelectronic Circuits (Sedra Smith 5th ed) and got stuck on 1.13 (voltage amplifiers) NOTE! This is not the end-chapter excercises included in the PDF solution manual! According to SedraSmith a voltage amplifier can be modeled as in the figure. The...
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    uC sourcing relay, a single darlington transistor or something else?

    Hey again! Don't mind post #3 I now know the answer to most of my questions. Except one.. You wrote that in case of the BJT in a common collector circuit I could skip the freewheeling diode. When I google relay + bjt 99% of the circuits i find are common-emitter (got that right?). But if you...
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    uC sourcing relay, a single darlington transistor or something else?

    So the BJT does not need a freewheeling diode? Or do both BJT and MOSFET need a freewheling diode? What is the purpose of the base series resistor? I'll look up thet common collector circuit Thanks FvM
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    uC sourcing relay, a single darlington transistor or something else?

    Hi EDA! I want to switch a relay with my uC. What options do I have? I'm new to transistors (and electronics in general =]) I'm using a PIC18F4550 and the relay I want to switch is a V23026A (TE-Connectivity). 1. I guess I can use the uC directly to switch the relay since it is possible to...
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    USB transient load question

    Yep the max is 500mA so 300mA would not be a problem regarding the max limit. However I did a simple test today with a switch and a 17Ohm resistor. When the resistor is not connect I measure 5.05V over the USB port. When I connect the resistor the voltage suddenly drops to 4.8 - 4.9V and stays...
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    USB transient load question

    Hi! Scenario: I have a USB port powering 20 relays and a microcontroller (uC) relaycontrol Relay current consumption ~15mA each uC current consumption ~1mA Questions: (I'm looking for the ways to calculate/model this theoretical, and what equations should I use) 1. If I have all the relays...
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    A question about bandwidth

    Hi! I have a question about bandwidths. The circuit I'm using is an analog multiplexer, ADG732BSUZ, and it has a typical "-3dB bandwidth of 18MHz" My understanding is that this means that if I have a 18MHz signal of 1V inputed to the switch (ADG732BSUZ) the output will be around 0.5V, is that...
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    Resistor power ratings

    Ahh okay, so a more proper load is for example 0.5Ω? And this small resistance would need to have a power rating of more than 288W?
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    Resistor power ratings

    Hi! I have a question about power ratings. This text is from www.allaboutcircuits.com "For checking large batteries such as an automobile (12 volt nominal) lead-acid battery, this may mean a resistor with a power rating of several hundred watts." The chapter is about battery ratings and how...

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