Toute ma partie ESP32 / programmation / prototypage est fonctionnelle, mais le problème est que les électrovannes sont en courant alternatif et qu'il faudrait que je puisse les faire fonctionner en courant continu (j'ai lu à différents endroits que c'était possible dans ce sens là mais avec en utilisant une tension + faible) mais je ne trouve pas la formule / calcul qui me permettrait de déterminer la tension (et l'ampérage) en courant continu qui correspondrait à ces caractéristiques du solénoïde :
Exigences de puissance du solénoïde 24 V CA 50/60 Hz (cycles par seconde) :
0,450 A d’intensité d’appel ;
0,25 A d’intensité de maintien
Résistance de la bobine de solénoïde : 38 ohms
Merci d'avance de votre réponse,
N'hésitez pas à me demander plus d'informations,
Cyryl.
[ENGLISH]
Hi,
I made a simple controller of 4 water channels (via 4 "RainBird 100-DV-A" solenoid valves) via 4 relays of this module (https://www.amazon.fr/dp/B07MJF9Z4K/?coliid= I17KT2YFEEKDWB&colid=36IVC3W6JW786&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it).
My entire ESP32 / programming / prototyping part is functional, but the problem is that the solenoid valves are in alternating current and I would need to be able to make them work in direct current (I read in different places that it was possible in this sense but with using a lower voltage) but I cannot find the formula / calculation which would allow me to determine the voltage (and the amperage) in direct current which would correspond to these characteristics of the solenoid:
24VAC 50/60Hz solenoid power requirements (cycles per second):
0.450 A inrush current;
0.25 A holding current
Solenoid coil resistance: 38 ohms
Thank you in advance for your response,
Do not hesitate to ask me for more information,
Cyryl.
My understanding is that it worked just fine for a few minutes. Then it was a downhill slide to ugly. Can you run a 24 VAC solenoid coil on a low DC voltage? Absolutely and I suggest doing as was suggested, starting with a low DC voltage and make sure the coil has no signs of getting hot. For a simple home project doing this is no problem, however, I would never do it in a commercial or industrial setting, I would use the correct 24 VDC coil solenoid.
Yes indeed a 24 VDC source. Actually it was a test stand I designed. I was out of town and someone figured that solenoid was the problem. Never looked at the drawings or materials called out. I placed that coil in my box of things I would show the technicians as to what not to do.
Well, that was my first idea of course but I can't find a 24 VDC solenoid valve with 1" for the diameter ...
I've looked on amazon AND on other sites but that seems impossible to find .
This is an example of a 24 VDC 1.0" NPT solenoid valve. All my applications were commercial industrial so I went with names like Asco, Red Hat, Parker Hanafin and similar. Most had removable coils so you could order just the coils and valve bodies seperately. Quality valves do not come cheaply.
Good find, but I was surprised to see that the coil consumes 24 W, and therefore generates a lot of heat. Indeed, that valve is not continuous duty. Maybe the restriction noted below is not important for the OP's application, but duty cycle is certainly something to be aware of, and to check carefully for any DC voltage valve being considered.
From the product page:
NOT a continuous duty valve and should NOT be in continuous use for more than 8 hours in a single cycle.
You can also reduce the current using a small resisitor to limit the hoding current
and a large value capacitor to supply the extra current needed (briefly) to pull in the solenoid.
So you think that with a 9VDC it won't heat up ?
Btw, any idea of the amps I should provide ? (one power supply of 2A is enough for the 4 valves no ?)
Sorry if my question is stupid, I'm quite new to electronics and still learning
As I've said several times, that has to be determined by experiment.
To find the steady state current, either measure it with your multimeter, or measure the valve coil resistance and divide that into the DC voltage applied (use Ohm's Law).
I placed that coil in my box of things I would show the technicians as to what not to do.
.