All Questions
40
questions
0
votes
4
answers
126
views
I have a solenoid rated at 24 volts AC, but at a trickle voltage of 1-9 volts the solenoid stays pulled in when it shouldn't be
I have a solenoid that pulls in at 24-30 volts ac to control water flow. It opens at 24 volts ac, but stays pulled in at a trickle voltage of .75 -1.0 volts. How can I stop this from happening?
0
votes
1
answer
163
views
Is this (working) 2-doorbell system dangerous?
In a previous setup, I had two doorbells, each one with its own 10V AC transformer, as detailed in Why is it impossible to connect these two doorbells in series or parallel?.
I now know it was ...
- 1,946
7
votes
3
answers
2k
views
Why is it impossible to connect these two doorbells in series or parallel?
I have:
one 220 V AC -> 10 V AC transformer
one push-button switch (at the door)
two bells for two different places of the house; they should ring together when the (single) door push-button ...
- 1,946
0
votes
1
answer
121
views
Thyristor external power supply
I am trying to make a kicker solenoid. My circuit is:
12 V battery connect to DC step up booster 300 V
diode
thyristor BTW69-1200 with external circuit (battery 1.5 V - resistor 1/4 W, 39 Ω)
...
- 465
4
votes
2
answers
248
views
Switching kicker solenoid with an idea out of the box
From my previous posting some may know I am planning to make a kicker solenoid.
The circuit specs:
Coil - 3.5 ��, 3.4 mH (inductance)
Capacitor 1000 μF, 450 V
DC booster up to 410 V
12 V DC battery
...
- 465
0
votes
1
answer
57
views
Relay rating for 390 V solenoid
I saw a video using car relay 12V/40A for a solenoid using 390 VDC and about 80A.
https://youtu.be/fVGrYoqn-EU
https://youtu.be/GsnxzMAczHU
I know relay can suppress the back-EMF from coil.
I want to ...
- 465
0
votes
3
answers
165
views
Calculating current a capacitor can deliver
I made a simple coilgun circuit
Capacitor 50 V 10000 uF
DC power supply of 20 V - 5 A
Coil of enamelled wire 18 AWG - 3.5 ohm
My calculations according to Ohm's law the current in the capacitor ...
- 465
6
votes
1
answer
969
views
Measure inductance of air core inductor
I am making an inductor
Air core
Wire: 18 AWG guage
Turns: (I am not sure ) but could be about 6000 turns
The weight of the wire : 400 gram
The coil wrapped by machine
Coil is 5 cm
Diameter of core ...
- 465
3
votes
1
answer
2k
views
Calculate the number of turns in air core inductor
Coil specification:
Air core coil
Length 790 mm
Diameter 290 mm
Wire guage 18 - 1 mm diameter
I need the number of turns to get an inductance of 150 mH.
While searching for calculating the number of ...
- 465
1
vote
4
answers
2k
views
Designing an RC snubber for AC solenoid lock (inductive load)
I am designing an AC solenoid lock. Here is my design:
Resistance 8 Ω
Main outlet power source 220 V - 50 Hz
Inductance 150 mH
Impedance 47 Ω
I (RMS) ~ 5 A
I read that the inductive load needs a ...
- 69
1
vote
1
answer
228
views
Designing AC kick solenoid lock
I am making a kick solenoid lock with AC.
I designed the circuit to run on 220 V, 50 Hz (household plug.)
The inductor (coil) is air core
500 turns, 150 meter (500 ft) in length with inductive ...
- 69
1
vote
2
answers
280
views
How to make a 220 V AC solenoid lock
I need to make a powerful solenoid lock using 220 V AC.
Let say I will use 21 gauge wire and get a length of 24 Ω. This will draw 9 A from the 220 V, so 1980 W.
This will be great force ...
- 465
2
votes
3
answers
689
views
Turns in solenoid coil or coilgun
more turns = increase in wire length = increase in resistance = decrease in current
So how come more coil turns will increase the strength of electromagnetic field?
- 69
0
votes
1
answer
159
views
Can I use AC voltage for a solenoid lock?
I want to make a very high force solenoid lock. I want to use AC over DC because the most voltage I can get from DC is 12 V (I don't have a power source supply more than 12 V).
So can I use AC to make ...
- 69
0
votes
1
answer
585
views
How does a camera flash get high voltage and current from a small battery?
I am a beginner trying to make coilgun. I see videos use camera flash circuit with capacitor that outputs 220V and a good current (5A) from 1.5V AAA battery
How does this circuit work to give this ...
