Questions tagged [thermal]

Relating to temperature rise, the flow of heat, or cooling of components

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30 views

Thermal Simulation Software

I'm looking for a thermal simulation tool that can be used for first order viability studies. For example, I'd be interested in simulating different enclosures with given internal heat load from ...
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193 views

Measuring transient thermal impedance

Context: output stage of Class-AB audio power amplifier. In the example schematic above, the output stage is biased in Class-AB via a bias voltage source. In use, output transistors will heat up ...
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3answers
205 views

Heat Dissipation Calculation for MOSFET

My challenge at the moment is dissipating 60A of load current through an array of MOSFETs. Here are my specs: No cooling fans Heatsinks allowed, if needed FET and/or heatsink cannot attach to the ...
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Component Height - Altium Designer

I'm using Altium Designer version 14.2. I am making a thermal analysis. The Analyze program expects a ODB++ format input from me. When I convert my PCB to ODB++, I can't see any height information ...
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p mosfet calculations reverse polarity for high power ( 48 V , 30 A )

i want to make reverse polarity protection for input 48 voltage , load 30 Ampere 2 dc buck converters. i was searching many solutions like diodes , but i wanna make it with p fet , so i came across ...
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Board is getting reset when I lower the temperature in Thermal Chamber

I have a board which I put in the thermal chamber. I increase the temperature inside the thermal chamber to 85degC. Soak it for 2 hours and note some readings. Then, when I change the temperature to ...
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How to use MLX90640 thermal camera code for a AMG8833 thermal camera?

So I want to use the AMG8833 sensor with my raspberry pi and some machine learning code, but the code was using the platypush package which is meant for the MLX90640 thermal camera. But after some ...
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2answers
62 views

Temperature Sensor Selection for temp range of 160C to 240C with 1C Accuracy

I am attempting to select a temperature sensor for a controlled heating application. The sensor will need to be inserted into a chamber with a cartridge heater and steel ball bearings inside of some ...
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56 views

How to simulate flip flop noise

Or is flip flop noisy at all? would you simluate its noise as you would do with a strong arm comparator? Why is strong arm comparator noisy but not a flip flop?
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Advice on thermoelectric generators

Hey everyone I was curious if you could help me. There maybe several questions in this so bear with me. Btw I am not an engineer so try and keep it simple please. What variables are needed to find how ...
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2answers
51 views

Thermal Vias Specification Design

An AD ADA4622-1 with LFCSP8 Package shows as Thermal Specification a "2 Layer Board with 2x2 Vias". What do this exactly means? It is a pcb for the exposed pad pin with 4 vias distributed as a 2x2 ...
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27 views

Thermal resistance of Thermal Interface Material

Can anyone please give information how to calculate the thermal resistance of SIL PAD "TSP A2000" from make Berguist. from The data sheet its specified thinness is 0.254mm, Thermal conductivity (W/m-...
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100 views

Does only wiring 2 poles of a 3 pole overload relay have any effect?

When wiring a single phase starter, they tend to jumper the overload such that all phases of the overload are used. Now, considering that the overload has 3 separate bimetal strips all connected to ...
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232 views

Warming PCB in cold environment using SMD components only

I made a sensor board that needs to operate at about -55 degrees Celcius. Unfortunately, its key component often malfunctions when the circuit is cooled for days at the temperature and then powered up....
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lm35 Temperature Reading increasing with Hot-melt adhesive (Calculations check needed?)

I have one question with this topic: lm35 Temperature Readings are not right after sealing with Hot-melt adhesive (How mush has it Soldering max Temp toleration ?) it answered by this (Thanks from @...
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Junction Temperature Estimation Error

When predicting the junction temperature (Tj) of semiconductor chips (for example IGBTs) by available thermal models such as FEM simulations, how much is the maximum permissible Tj estimation error ...
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84 views

Why are there no nichrome resistor pastes?

Nichrome wire is commonly used for wire coil heating elements. Other heating elements are formed by screen printing a pattern of "resistor paste" onto a dielectric coated substrate. These pastes are ...
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3answers
132 views

Heatsink on top of SMD plastic IC or bottom of PCB?

I often do designing power modules and always wonder if there is some kind of rule how to properly cool SMD devices. I always look at final products from other companies and some are placing heatsink ...
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1answer
78 views

How to power a nickel chromium wire to produce heat without burning the power adpapter

I want to build a toaster just for fun. I want to buy a nickel chromium wire to heat the toaster's plate. How to avoid burning my power adapter cuz the resistance is too low. I currently have a ...
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270 views

Very high temperature (>500C) IC packages

I was looking for IC packages where I can mount a small wafer (3mmx3mm) wire bond to the leads of the package and conduct operation at 500C. I have contacted couple of companies which do ceramic IC ...
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107 views

Interpreting results of a thermal camera - what should I expect to be hot?

I'm not a trained electrician, but I got my hands on a thermal camera to play with. Its existing documentation didn't help me quite understand what's going on when I see a hotspot. What components can ...
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4answers
428 views

How do thermal tapes transfer heat despite their low thermal conductivity?

I found myself needing to attach small heatsinks to Mosfets and CC power regulators. Also some high-power diodes. Today I have learnt that thermal compounds, even best in the market, are dozens of ...
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3answers
100 views

Do unused relay pins help with heat dissipation?

I have been using DPDT relays to control high-current loads (~15 A at 240 Vrms) though I am only using them in a SPST, NO fashion; that is, the load is disconnected when the coil is de-energized, and ...
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2answers
58 views

Thermal noise voltage measured by an impedance matched ADC

I have a question regarding the thermal noise voltage measured by an impedance matched ADC. In the figure above, I have a simplified circuit with a source impedance (on the left) and an ADC (on the ...
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1answer
220 views

Will PCB board house accept this QFN thermal pad via design (KiCad)?

I am going to be ordering this board from JLCPCB which has some 0.2 mm hole diameter thermal vias on a QFN pad, and it says on their capabilities page that the smallest via hole size is 0.3 mm, BUT ...
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How to calculate MOSFET temperature increase in PCB

I want to calculate MOSFET(DATASHEET) temperature increase for PCB. MOSFET - FDD86250_F085-D Totally 13 MOSFET's will be mounted in PCB. At the same time, maximum 8 MOSFET's will be used in PCB 1, ...
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1answer
72 views

The Thermal relief consideration for TVS diode (for ESD protection)

I am designing a print which has some mircofit connectors, I have placed TVS very close to the connectors on the print and the ground pad connected with a GND polygon directly, this polyon connects ...
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3answers
53 views

Need help in cable temperature calculations

I am trying to calculate how hot will a 0.6m long 28AWG wire carrying a load of 12VDC, 0.2A get. I understand that are other factors such as environment cooling rate, thermal resistance between air ...
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49 views

Calculating Junction Temp of Switching Regulator

I was looking at TI web bench to find a regulator, my question is my calculation is correct and if it is why we have different value on webbench. The IC is TPS565208 P = (Vout - Vin)*Iout => (12-...
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Infineon IPOSIM tool for IGBT thermal loss calculations

I used the infineon IPOSIM power tool for simulating a motor drive for my required conditions and got the results for a custom input drive cycle. The results were given as power dissipation per IGBT(...
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1answer
39 views

Application based Heat sink design for Power diode

Instead of having a heatsink directly connected to the diode, I want to have a 2 mm layer of cold rolled steel in between case and heat sink(aluminium){for waterproofing as needed in the application}. ...
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647 views

Heatsink on underside of PCB

I have prototyped some DC-DC converter modules, and they work well. However due to size, I don't have a huge amount of copper pour for them to dissipate their heat. I have used 2oz copper but the ...
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1answer
57 views

Would leakage through a JFET create thermal noise

The impedance through the gate of a JFET is very high and leakage current very small. Would this impedance act like a large resistor creating thermal noise? Would this be a low noise way of ...
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1answer
89 views

Colpitts oscillator: how to reduce amplitude thermal drift?

I have built this circuit, supply ±12V: I am using a LM6172 amplifier. I have found the transfer function of the filter involved: \$H(j\omega)=\frac{1}{1 + \frac{R_3}{R_1} - L\omega^2(C_2+C_1\frac{...
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21 views

Heat transfer coefficient in a Module Baseplate

Today, for example in a power IGBT module cooled by a heatsink, it has been found that the heat transfer coefficient (htc) distribution may not be uniform across the bottom surface of the module ...
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1answer
49 views

Thermal resistance Junction - Maximum Power dissipation

I want to understand the real meaning of the parameter 'Thermal Resistance Junction to Air (°C/W) to calculate the power dissipation. So for example if the value of this parameter is 250°C/W, should I ...
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1answer
64 views

Resources for finding thermal impedances for common IC packages

I'm just looking for some extra resources for thermal impedances of JEDEC standardized packages. I've already found one such article posted by JRC, https://www.njr.com/semicon/package/thermal.html , ...
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99 views

Thermal Glue solvent

I have a PCB with many chips on it - it's a "hashboard" for an ASIC bitcoin miner. There are 63 chips on every hashboard, and each chip has a small heatsink on it. I tried heating the heatsinks with ...
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2answers
67 views

POWER MOSFET - Thermal Design

i have some doubts about with this thermal design? first, the calculations and infos: My load (a motor) uses an average current of 7A, I could not measure the current peak at the beginning of the ...
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1answer
46 views

Wire gauge and combined wires for 3D printer hotend through PCB

So I've been designing a wiring harness PCB for my 3D printer to provide connections and easily swappable tools. I settled on a TE 34-pin connector to use as input on the PCB. The current design ...
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1answer
101 views

LD1117V33 voltage regulator heatsink, thermal paste needed?

I want to screw a heatsink to my LD1117V33 voltage regulator. It's a normal 3mm screw and nothing inbetween. Do I need to use thermal paste or something like that? It will be regulating 12V down to 3....
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1answer
69 views

Water-Based Heat Sink

I am trying to incorporate a TEC in a portable system. The heat from the interior of the system needs to be transfered to the exterior where it can be dissipated freely into the environment. Now, I ...
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1answer
41 views

Cold activated heater control

I would like to build a simple control circuit for a 12v silicone heating pad. I think what I'm looking to make is a thermally controlled relay: I want current to flow when the temperature is below ...
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1answer
79 views

Circuit thermal analysis in PSPICE and temperature coefficients

I am tying to perform a thermal analysis in pspice. Resistors needs two temperature coefficients as TC1 and TC2 (if we assume linear change of R vs. T, it's zero) in pspice. But in resistor datasheets ...
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290 views

What is reasoning behind the common wisdom of limiting the temperature rise of a PCB trace to 5/10/20°C?

When deciding on the trace thickness required to carry a certain amount of current on a PCB, the answer depends on how much temperature rise you are willing to accept. This leads the designer into the ...
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105 views

Understanding the thermal images of planar pcb coils

Why is only the first turn in the coil hotter compared to other two turns? In this, only the turns of the top part seem to be hotter compared to the bottom. Current through the coils is 2 A. It is ...
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1answer
58 views

General Peltier-tivity

[EDIT: Found a couple of 12715 units in the pile that did suck the full amperage, but despite excellent cooling of the hot side, could not deliver much cooling.] I'm waist deep in project to keep ...
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1answer
45 views

Open-circuit alternator

Is it dangerous to run a permanent magnet alternator open-circuited? No current can flow so is all the power dissipated as heat? Is there even power generated in the inductive coils?
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Modeling the thermal part of the Time-current curve

G’ day, I am working on designing protection devices for my research work and I am struggling to model the thermal part for the low voltage circuit breakers based on IEC standards. Based on the ...
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1answer
61 views

Is there a difference between a tempco resistor and a thermistor?

That is, other than just the nomenclature.