That engineer was wrong.an engineer with me told me a resistance of 10 ohm is like a resistance inductance of 10 ohm. is it possible to replace an inductance by a resistance in electronic terms? for me in EMC terms we can't.
inductance has a resistance that is due to wires and a binding capacity. when the current is continuous the inductance behaves like a resistance. in this circuit I use an inductance to filter the current at high frequency what are called peaks that can be generated by the relay inductance during switching. this was my reasoning.I think we have a terminology problem:
Inductors are rated in Henrys, not Ohms.
This entire thread seems to ignore this obvious problem?
An inductor will have resistance, it's resistance is relevant, but that alone does not tell the complete story.
What is the part number of this inductor in the circuit?
hi,hi oua,
My advice is to remove the 40 Ohm inductor in the 5v power line.
E
This is a common problem with spikes on the net.First of all, I would like to thank all the members of this forum who share their knowledge without hesitation.
my problem is the crash of a microcontroller.
Indeed, I control relays from a microcontroller but my problem is that after some relay switching my microcontroller crashes and resets.
I use as decoupling circuit a 40 ohm inductance and two parallel capacitors of 47 uF and 100 nF.
the control voltage is 5V.
do you have any suggestions?
This is a common problem with spikes on the net.
If you feed the cpu circuit via a fast switching diode and load a capacitor(eq 100uf) then a new power supply is created. the relay coil is connected direct to the 5v supply. That 5V input line should carry a elco as well.
The coil does 40mA approx @ 5 V calculate c for 5 rc times R=5V/40 *10^3 ( dc resistance coil see spec sheet)
When a voltage drop(spike) occurs the power goes low but the cpu keeps running from the capacitor.
Do not forget to add 100nf to all caps above 10uF ( used in the power circuit).
Advice: try to use Mosfets to control relays.( low impedance low lost less heat)
I didn't understand your suggestion.
Picbuster
That's why we use a special type of inductor for EMC/EMI. We need one that is dissipative using the field method. Ferrite bead/core chokes are designed to provide this function. Loss in the form of resistance in the ferrite itself to the changing magnetic field. This dissipates the noise energy in the form of heat.That engineer was wrong.
resistance is in ohms, and inductance is in ohms, and they both refer to controlling the flow of current (impeding it), but they do it differently.
Resistor (aka resistance method): Friction slows electrons down, dissipates excess as heat.
Inductor (field method): negative polarized field repels negative electron field, no heat generated.
I don't have to check this component or even think about doing it. it is +CWAAIC1 looks like a power-on reset and power monitor device. Have you looked at it's output to see if it is switching in response to something on the 5V power? What device is it? If it is switching maybe you can go back from there?
+CWAA?I don't have to check this component or even think about doing it. it is +CWAA
Let me explain. Discussion has been aimed at the 5V power to the microcontroller. When I look at the circuit, I wonder if IC1 is involved. The idea is:[QUOTE = "Analog Ground, post: 1416309, membre: 621225"] + CWAA? [/ QUOTE]
Microprocessor Reset Circuits
Inductors are rated in Henrys, but reactance is still in Ohms. A Henry is probably beyond what the OP would be able to use, yet, because a Henry is described as the rate of change of current equal to one ampere per second, resulting in the Electromotive Force (EMF) of 1 Volt, which means we also have to get into WebersI think we have a terminology problem:
Inductors are rated in Henrys, not Ohms.
This entire thread seems to ignore this obvious problem?
An inductor will have resistance, it's resistance is relevant, but that alone does not tell the complete story.
What is the part number of this inductor in the circuit?
No, you are wrong.inductance has a resistance that is due to wires and a binding capacity. when the current is continuous the inductance behaves like a resistance. in this circuit I use an inductance to filter the current at high frequency what are called peaks that can be generated by the relay inductance during switching. this was my reasoning.
View attachment 182356
by Don Wilcher
by Jake Hertz
by Jake Hertz