Slowing solenoid action?

Started by Terry Pinnell in sci.electronics.design3 years ago 33 replies

Is it possible, perhaps using PWM, to slow down the action of a solenoid while still maintaining most of its force? By way of background, I'm...

Is it possible, perhaps using PWM, to slow down the action of a solenoid while still maintaining most of its force? By way of background, I'm considering a solenoid for pressing a rather firm button. The only one I have at present that can do so reliably is a 24V type that delivers its press too fast and too noisily. Lower voltage types (already owned or researched on ebay or Amazon) seem t...


electron beam through solenoid coil

Started by Jamie M in sci.electronics.design11 years ago 13 replies

Hi, How does a solenoid act to focus a beam of electrons that are passed axially through the coil? cheers, Jamie

Hi, How does a solenoid act to focus a beam of electrons that are passed axially through the coil? cheers, Jamie


Two pulses with long gap: simplest circuit?

Started by Anonymous in sci.electronics.design4 years ago 34 replies

Project: To get images with my iPhone 6S+ of a fox visiting our garden overnight. One approach I’m considering is to tap the button of a...

Project: To get images with my iPhone 6S+ of a fox visiting our garden overnight. One approach I’m considering is to tap the button of a Bluetooth camera shutter gadget (from CAMKIX) with a 500 ms pulse to a solenoid, triggered in various ways. (I don’t want to crack open the tiny case to attempt that with a circuit mod.) That seems reasonably straightforward. But


Re: LTspice question: modelling a solenoid

Started by Phil Allison in sci.electronics.design13 years ago 23 replies

"John Nagle" > I need to model the "selector magnet" of a Model 15 Teletype. > This is an electromagnet with an iron core. > DC...

"John Nagle" > I need to model the "selector magnet" of a Model 15 Teletype. > This is an electromagnet with an iron core. > DC resistance is 55 ohms. Inductance is 4 Henries. ** How did yo get that 4H figure?? Iron core solenoids are not pure inductors - they are "lossy inductors" with phase angles of about 45 degrees. ... Phil


txlines

Started by Anonymous in sci.electronics.design1 year ago 40 replies

Everything that conducts is a lossy transmission line. A solenoid inductor. https://www.dropbox.com/s/b5eae1jwsdscw4k/PC_3.jpg?raw=1 A...

Everything that conducts is a lossy transmission line. A solenoid inductor. https://www.dropbox.com/s/b5eae1jwsdscw4k/PC_3.jpg?raw=1 A series string of surface-mount resistors. A ground plane or power pour. A wound-foil capacitor. A wirewound resistor. A piece of wire in free air. A via. A pcb trace, of course. -- Father Brown's figure remained quite dark and ...


Dual Offest Sub-audio Test Signal

Started by Anonymous in sci.electronics.design8 years ago 41 replies

Can someone please help with this project. I am unable to find anything similar in the form of an existing design. The objective is to apply...

Can someone please help with this project. I am unable to find anything similar in the form of an existing design. The objective is to apply a 10Hz test signal, generated with a lab function generator, to two air core solenoids of 50R. OK, here is the different part. One solenoid must be fed with a positive offset signal, and the second with an identical negative offset signal. Gi...


arc suppressor for relays

Started by Jon Elson in sci.electronics.design10 years ago 36 replies

We have one of those $1K high efficiency washing machines. It does work, and clearly reduced our water and gas bill, so I'm not...

We have one of those $1K high efficiency washing machines. It does work, and clearly reduced our water and gas bill, so I'm not complaining. Lately, it has been getting "slow fill" errors, and I tried a bunch of typical stuff before finding the REAL problem. They have a bank of electromechanical relays to operate a bank of solenoid water valves. There is no arc suppression on these relays,...