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1 vote

LM317-N output voltage lower than expected in LTspice Simulation

Kevin has already addressed your main question. I just want to point out a couple of things: To your follow-up question: "After adjusting to 88, my result gets a lot closer but still slightly ...
Blair Fonville's user avatar
2 votes
Accepted

LM317-N output voltage lower than expected in LTspice Simulation

Your Iadj part of the calculation is wrong. Iadj is a fixed value of about 50uA (from datasheet) - it can be ignored with low value resistors such as what you are using. The equation then reduces to ...
Kevin White's user avatar
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0 votes

Using a battery charger module to replace Li-ion battery. Is this safe?

Is it safe to connect the 4.2v output of the charger module to where battery was connected? Apart from safety, you'll probably have operational issues. TP4056 is a self-adjusting voltage and current ...
Rohat Kılıç's user avatar
2 votes

LCD PCB component identification, SOT-23-5, "DK-NON"

The ultimate SMD marking codes database page for marking codes starting with DK shows several results for DK-. The only result ...
Chester Gillon's user avatar
0 votes

Voltage regulator output signal becomes noisy when connected to a CPU

on page 20 of the datasheet they show some typical transient response of the regulator, which is not that different from your measurements. The quoted 3A current is a maximum DC out and hasn't got ...
danmcb's user avatar
  • 7,052
0 votes

producing -2.5V from -12V using LM4040

The LM4040 is not a simple diode but a sophisticated integrated circuit incorporating a bandgap reference to make a shunt regulator. As the datasheet linked above shows, this is the simplified ...
Spehro Pefhany's user avatar
0 votes

producing -2.5V from -12V using LM4040

The LM4040 is not just a simple diode it is a precision shunt voltage regulator which can be modeled as an accurate Zener diode from terminal 2 to 1. As the voltage on the -2.5V line rises pulled up ...
RoyC's user avatar
  • 10k
1 vote

Isolating Power Fluctuations and Buck Converters

Try connecting a diode (e.g. 1N4001, or a Schottky diode) between the output of the 9V supply and the input of the 5V one. Then add a capacitor to the input of the 5V. This way, if a large load ...
jp314's user avatar
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1 vote

Isolating Power Fluctuations and Buck Converters

It's possible your battery is momentarily dipping below the ESP32 regulator's 'power ok' voltage (maybe 7V or so if it's an LM317 type.) Try a regulator type that has a lower dropout. The other ...
hacktastical's user avatar
  • 54.1k
0 votes

Why my ESP32-CAM won't power up with 5 volts?

Just Simply connect the +ive of the battery to the 5v pin on the esp32 cam not the 3v3 pin, and -ive of the battery to the gnd besides the 5v pin on the esp32 cam. The regulator on the esp32 cam board ...
Manojna M Vinay's user avatar
1 vote

What is the disadvantage of using a boost converter?

In addition to other answers... All switching power supplies are a concern for EMC. Significant care needs to be taken to avoid your PCB or other components becoming a radio broadcasting at the ...
Graham's user avatar
  • 6,150
5 votes

What is the disadvantage of using a boost converter?

For a voltage multiplier, the output voltage depends on the input voltage and losses.$$V_{out}=K{ }V_{in}-V_{\text{losses}}$$ For a boost converter, the output voltage is independent from the input ...
RussellH's user avatar
  • 15k
3 votes

What is the disadvantage of using a boost converter?

You can indeed use something like a DC-DC converter to obtain an appropriate voltage for some element, from a source of inappropriate voltage, but there are power and current considerations, which I'...
Simon Fitch's user avatar
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7 votes
Accepted

What is the disadvantage of using a boost converter?

A boost converter can increase the output voltage however this is at the cost of needing more supply current. Ignoring losses Vin x Iin = Vout x Iout. So if you where say increasing 5V to 10V your ...
RoyC's user avatar
  • 10k
2 votes
Accepted

What's the best way to make sure I have a known VCC on a battery powered device?

Essentially, you have the choice between switching regulators and linear regulators with LDOs being just a flavor of linear regulators. If efficiency is a concern, you maybe want to use a switching ...
feynman's user avatar
  • 3,355
2 votes

Identify diode specs

Manufacturer: Rohm Semiconductor Manufacturer part number: RB051L-40 (obsolete) or RB051LAM-40 (active) or a clone of them Data sheet: RB051L-40, RB051LAM-40 Distributor link: click Part Type: ...
CatastrophicFailure's user avatar
0 votes

Can I hook up a 9V unregulated power supply to a 9V voltage regulator to stabilize the output?

I recently built this 5 - 30-mimute timer circuit (https://www.elprocus.com/30-minute-timer-with-circuit-diagram-using-555-ic-7555-ic/) and decided to power it with a 9V, 200mA unregulated wall wart ...
Explorer's user avatar
0 votes

How to calculate current limiter resistor when voltage regulator is involved?

You say you want high efficiency, and 5V output at 1A, with 2S lithium pack. These are not going to happen with a linear regulator like HT7850 LDO. The lithium pack will be at 8.4V when fully charged, ...
Justme's user avatar
  • 148k
1 vote

Effect of source/input impedance on LDO regulator stability

While I haven't delved much into this, I feel that the problem LDO regulators have with stability is related to the gain of the pass element being highly variable in a common source setup (below right,...
Simon Fitch's user avatar
  • 35.1k
0 votes
Accepted

TPS564247 switching voltage regulator problem

Update: It is working now flawlessly. Some legs did not touch the pads on the PCB so some rework fixed the circuit.
Saláta Szalonna's user avatar
0 votes

How to calculate current limiter resistor when voltage regulator is involved?

I don't believe you need a resistor between the base of Tr1 and R1. In the question you linked, a resistor was needed to protect the relatively fragile GPIO pins of a microprocessor. You have nothing ...
Math Keeps Me Busy's user avatar
0 votes
Accepted

How to calculate current limiter resistor when voltage regulator is involved?

A simpler approach would be putting 2 of these devices in parallel. 3 would be even better from a reliability and thermal management standpoint. Simpler still, would be to use a 1.5A 3-term regulator ...
MOSFET's user avatar
  • 3,040
2 votes
Accepted

Can I supply 3.3V to a 4V stepper motor?

Try powering the motor from 3.3 V. Nothing is going to get damaged. It will operate at slightly reduced maximum current, and hence torque. With a lower voltage, it won't step quite as quickly. Unless ...
Neil_UK's user avatar
  • 166k
1 vote

Can I supply 3.3V to a 4V stepper motor?

Can I supply the motor with a 3.3V voltage for simplicity Well, you can but you'll lose torque and maximum speed. ... or do I need two separate buck converters: a 4V for the motor and a 3.3V for the ...
Rohat Kılıç's user avatar

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