Suggestion: Adjust the program so that full voltage (14V!) is applied for enough time to allow the relay to pull-in fully, then apply PWM at > 20% coil volts.
Regards,
For comparison, you could evaluate the voltage drop across each type joint at a selected load (constant current). The clamping force should be sufficient to handle the peak current and other environmental issues, such as the Amb. Temp. and shock & vibration.
Test is best.
Regards,
You could consider an electromagnetic solution whereby you could adjust the strength of the field.
For comparison purposes you could measure the pull or separating force that was required to separate a piece of iron/steel from your drum. A simple force gauge or spring gauge that could hold the...
Hello,
I’ve always understood that SSR’s are not considered fail safe for this type of application. Perhaps someone can enlighten me if I have been misinformed.
Is this a series wound motor(kW)?
What is the nominal running current, and expected ‘in-rush/start-up current? How inductive is it...
Alternatively, you could assess some of the Albright range of contactors – maybe one the SW80B series.
http://www.albrightinternational.com/lang/en/index.html
Regards,
1. I had provided those values from experience. You can find all the formulae you need on Wikipedia or , for example, www.magnetapplications.com The formulae will get you so far, but there is no substitute for the actual tests that must be performed.
2. I’d guesstimate that an ½” Dia X ¼”...
Hi Ktysai,
Yes, that’s correct.
A Neo. magnet (3/4” Dia. x 3/16” thick) should provide a hold in excess of 90N. A 1000 ampere-turns coil should destabilise the flux sufficiently for the release of the spring mechanism.
The actual size of your magnet and coil will depend upon your application...
Suggestion: A permanent magnet (such as a neodymium) could be utilised to keep your spring compressed. If a coil was wound around the magnet, the magnet could be momentarily demagnetised when current flows through your coil - thus releasing your spring.
Regards,
This may be a bit late in the day, but you could try using a series capacitor to simulate the instantaneous current of the pump-motor (DC series wound). The amplitude of the inrush can be controlled with a resistor, i.e. pre-charged capacitor. This may save a few bucks.
Regards,
Question for Sreid: how does a ‘metallic arc’ differ from an ‘arc’?
It is my understanding that:
[a] ‘Blowouts’ are generally used to break the arc upon contact opening.
[b] Basically, the nature of the arc will be determined by the circuit, contacts & atmospheric conditions.
[c] When...
Thanks Mike.
I can confirm that I will be able to generate enough A-ts to saturate the frame. Also, to be clear, I should have mentioned that this is a DC solenoid.
I was hoping the exp will also show me how much power is required to fully saturate the frame, and to define the point on the...
Is it feasible to determine whether or not a magnetic frame is saturated by the following experiment?
Device: A small solenoid, approx 1.5inch by 2.0inch.
Method:
The solenoid is secured in a non-magnetic fixture.
The armature position is fixed half way along its stoke. [full stroke approx...
