# Questions tagged [heat]

Thermal energy; where it comes from, and how to keep it from damaging components

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### Estimate Total Heat Generation per LED for CFD boundary condition

I am designing a lampshade to house a 240v 14W 6500K LED bulb and simulating the heat generated in and around the lampshade using CFD. I need to know how many watts each of the 26 LEDs is using but ...
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1 vote
99 views

### Should I use a DC-DC converter or an LDO?

In my project, I am designing a board which is supplied by a battery. The battery is a LiPo, 3.7 V, 1000 mAh, so its voltage range is 3 - 4.2 V. All the components on the board need a fixed voltage of ...
• 467
141 views

### How can I best reduce the current drawn by a PCB heatbed?

I have a noob question about fairly basic circuit design (I think). I am building an incubator for making Tempeh at home, and want to use an old PCB heatbed I have lying around as the heating element. ...
2k views

### One of four MOSFET in parallel heating too much

I am doing an electronic load project in which I need to work with four MOSFETs in parallel working in the ohmic region (not switching). I have a good heat sink. Furthermore, only one of the four ...
• 355
1 vote
40 views

### Improve thermal effeciency of buck LED driver with fixed supply rail

I have this driver circuit that uses an ILD8150: There are two identical sections of this module on my PCB. One powers 6 LEDs the other powers only 2 LED. The Vf of the LEDs is 2.85V @ 350 mA. So the ...
• 875
546 views

### Wire resistivity / heat generation

How to calculate the volts/amps of a battery which is connected to a simple wire for heat generation? That is, how to use: known wire length, diameter/area, resistivity to calculate the required volts/...
1 vote
70 views

### Can I replace a 12 V 40 W heating element with several 12 V 7 W elements?

Here is the environment: An RV fridge has a heat exchanger for cooling, looks like what you would stick on an IC chip, only 12" square. It has heater stuck on the back of it that is activated for ...
• 113
42 views

### Temperature measurement in strong AC magnetic field

I have a coil that is continously driven with a maximum of 100A RMS of current at a frequency of 20kHz. The coil is water-cooled and I would like to directly monitor its temperature. The temperature ...
142 views

### Blocking oscillator, Slayer exciter drawing too much power

I am trying to build one of these using an air-core coil. I got it oscillating but have to cut power off after 4 seconds as it starts to heat up (can't hold it with my fingers.) The transistor is not ...
• 11
1 vote
54 views

### Load testing using a resistor bank

I have a bespoke 48V down converter that I'm looking to test which should be able to provide a maximum of 500W of power. I'm looking to test the device under various loads - from 50W to 500W. I'm ...
1 vote
47 views

### Reduce the heat output of a MOSFET (buck LM5085)

First of all I have to say that I am a beginner, and I don't have an oscilloscope to work with. Just a multimeter. I'm trying to design a PoE+ board with a 9.5 V @ 3 A output. The PoE+ part works fine ...
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### Calculating how much nichrome wire rod is required to heat aluminium at 490°C [closed]

My purpose is to install nichrome wire rod in an aluminium annealing furnace with capacity of annealing 3800kgs of aluminium. The furnace is well insulated. It has two built in blowers to circulate ...
45 views

### Clone 862D+ soldering iron heating element

I purchased an ebay 862D+ rework station in 2017 and it has worked great. Recently I broke the ceramic on the heating element but did not break the element itself so I was able to get ohm readings ...
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68 views

### What variable power electronic to use for boiler heater?

I am running a PV-Solar system together with a heat-pump in Germany. Excess electric power is fed into the grid, however I am only allowed to feed in 70% of the peak capacity. During solar noon, I ...
• 131
885 views

### Where does all the electric energy get dissipated in any electrical system?

I know that some portion of the electrical energy is dissipated as heat due to the efficiency, but where does the other energy go? If we are talking about a satellite in space, all of the electrical ...
52 views

### Heat produced on breadboard power rails with 1 vs 2 loads

Lets say we have a 12V power source connected to a single load, and 2.4 amps go through this wire. The wire will heat up. Now the same 12V source, but now there’s two loads, each pulling 1.2 amps each....
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56 views

### How to calculate expected temperature of a heating element?

I have a problem. I am suspecting heating mat I got is not working. It is barely warm to the touch, to the point I wonder if I'm imagining it. It's parameters are 230V, 16W, 26.5 x 28 cm. It's flat ...
• 420
107 views

### Can't get 12V PTC heating element to work

Please bear with me as I am a complete beginner. I am planning on using a PTC heating element in a project. Here is the link to the one I bought on Ebay: Aluminium enclosed 12V 80W PTC Heater/Heating ...
87 views

### LED lights become darker? [closed]

I build myself a light with many small LEDs. They are quite powerful. I superglued ever LED board (the LEDs where in parts of 3 on a small circuit board) to an aluminium piece to dissipate the heat. ...
158 views

### Why can't my kiln reach the needed temperature?

I'm building an electric kiln to melt metals like lead aluminum, and maybe even copper. I have no experience or professional knowledge on the subject. I want to be able to reach at least 1100°C but ...
234 views

### Why is the thermal conductivity of FR4 shown to have two different values? (Based on heat flow direction)

Reference Why would thermal properties of a material (FR4) depend on direction of heat flow?
• 2,051
276 views

### Super-capacitors to heat resistive wire

I am looking for help/insight into the feasibility of using the stored energy in supercaps to heat a short length of nichrome wire, or a vape coil. I have nichrome wire that is 0.040 size, at 0.408 ...
1 vote
123 views

### How to reduce 48 V to 32 V on a PCB? [closed]

I need to supply an evaluation kit (a motor driver) at 32 VDC +- 10 % from a 48 VDC battery. In the datasheet it is stated: The power supply has to be thermally designed to withstand the nominal ...
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1 vote
61 views

### What generates more heat: inverting to 0s or to 1s in Flash memory?

I was not able to find an answer via web search. The question came to my head after reading https://www.networkworld.com/article/3049428/humidity-not-heat-is-a-hard-drives-biggest-threat.html: The ...
175 views

### Why is my DC/DC converter getting super hot?

I need to supply an evaluation kit at 32 VDC +- 10 % from a 48 VDC battery. The power supply of the kit is rated at 60 W with spikes at 150 W lasting 100 ms (it controls motors). I have choosen the ...
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112 views

### PCB design, 30 5 V LEDs per board (probably 6)

It's my first time designing a PCB. I had the idea to make a pyramid out of (probably) 6 same PCBs. Each pyramid would have 30 WS2812B B LEDs. Online I read that on the one side you should be ...
44 views

### Crimp vs stainless steel intermediary for copper and nichrome connections in a heating element. Any difference in speed of heating?

I'm designing an electric furnace to melt aluminium. I'm planning to use the heating element from an electric oven. I'm aware that the melting temp for aluminium is lower than copper BUT I don't want ...
65 views

### Controlling a kiln with PID and old magnetic contactor

I have retrofitted an old 240V/16A kiln with a controller consisting of an INKBIRD ITC-100VH, a FOTEK SSR-40 and K-type thermocouple in line with VegOilGuy's guide: https://www.vegoilguy.co.uk/...
83 views

### Arduino NANO heating issue

I am trying use a HMI display with arduino NANO. I am powering arduino and hmi display ( topway 5 inch smart display ) with 9 volt adaptor. everyting works fine. but if I plugin the Tx, Rx pins which ...
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1 vote
127 views

### How does a usb heating pad work

Here is a picture of 2 usb heating pads : As far as I can understand, 5 volts come from the usb, go into the curly wires, which produce heat since they are like a long resistor that dissipate power. ...
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73 views

### relays 5V 10A and 12V 30V stop working after a few days of use

We built a system for heating 3 bioelectrochemical reactors, but after a certain time of operation the system starts to heat up. We identified that when this occurs, the relay works despite the light ...
1 vote
47 views

### Can I control a solenoid valve below its nominal voltage?

I need to control the following 2 ways direct solenoid valve ("Series 252 D01") : https://www.emerson.com/documents/automation/catalog-series-252-dental-manifolds-asco-en-6779448.pdf It is ...
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1 vote
182 views

### Resistor in my AC LED circuit gets fried

I have designed a dead simple LED circuit I calculated the required resistance to be (220-2)/0.02 = ~11k so I used 10k+1k resistors in series but for some reason, ...
• 113
1 vote
136 views

### 0805 package SMT pads minimum clearance and tombstoning

The picture shows 0805 LEDs and one last 0805 resistor connected to the GND pour. What is the minimum clearance between the SMT pads of the different 0805 LEDs that I should consider safe for ...
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73 views

### PCB via array for "better" heat dissipation

My two PCB mount power supplies are getting quite hot (temp 60 to 70 degrees). Max temp of the power supply is 90 degrees. I cannot use external heatsinks due to space constraints. Input voltage is ...
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137 views

### Is my circuit analysis correct? (DC, LED, LED driver, MOSFET)

Hello, please shed some light if my analysis is correct regarding the circuit. It is a DC circuit with an LED, LED driver and MOSFET. I'm initially getting 24V power into my PCB from a AC/DC wall ...
• 3
83 views

### Is there a "rule of thumb" for power dissipation of an enclosed circuit to help determine when to do a thorough analysis?

I'm starting a project and the electronics will be enclosed in a wood sign outside. Even though it's shaded, I'm concerned about heat buildup in the summer. Is there some rule of thumb that says if ...
45 views

### PCB Trace Temperature Rise Model Question

I am reading an analysis on circuit board trace heating, and have found a source for a general temp rise vs current equation that matches measured IPC 2152 closely. However, I am having trouble ...
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94 views

### How/where does a generator + motor dissipate heat?

I've got a mystery that I can't wrap my head around. A generator is generating 1 kW of electric power. The current goes through copper cables to a motor, which is consuming say 950 W of electric power....
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73 views

### Clarification: the role of resistance in producing heat / light (e.g. incandescent lightbulb)

I'm reading Code: The Hidden Language of Computer Software to get a better understanding of what makes a computer work. Early on there is some elementary explanation of what electricity is, and how we ...
113 views

### In DC-DC converters, how can the ripple current affect the circuit's performance?

I have a DC-DC buck boost converter (TPS55288) that I was planning on using for a project. I'm making a revision to my current heated gloves, and my circuit needs to be as small as possible since the ...
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77 views

### Mounting Emitter ballast resistor close to the power transistor

I am helping one of my HAM radio friends to build a 25 A, 13.8 V linear reg power supply. As commonly done, I am using the parallel power transistors to deliver the current and to limit thermal ...
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78 views

### How can I estimate heat generation of a DC regulator

I've added a small 12V LED light strip to my 3D printer which has 24VDC output. The LEDs have current limiting resistors and with the spec sheet I estimated the current draw to be 200mA. I had a ...
• 103
1 vote
229 views

### Nature of resistance, cable length and heat

I am struggling to understand the nature of the relation between resistance, heat and the length of the cable. In the scenario where a battery is short-circuited, a short cable will heat up ...
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115 views

### LDO power dissipation

I am trying to design a split power supply from lithium-ion batteries to use with different portable audio projects. In order to have a stable power source, since it comes from batteries, it has to be ...
1 vote
70 views

### Thermal protection of triac in floor heating controller

Hello there fellow engineers. I'm in the middle of design controller for floor heating. The idea is to have a triac based design with zero detection circuit, for each control point (each heating cable ...
67 views

### Wire heating from microwave signal

How would one calculate the temperature change in a wire into which a microwave signal of a given frequency and power is applied?
1k views

### Formula to calculate wattage required to heat stainless steel?

Original Scope: I am trying to make a heating element using a 304 stainless steel flat bar for simplicity. I'm choosing stainless steel instead of nichrome since it will be more durable. If I know its ...
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