Relays vs. zero crossing triggers? Can the same relay be controlled by the relay without fire?

The relay can also be triggered by "zero crossing", of course, because of the "delay", it is necessary to send a control signal in advance - a certain time before the voltage crosses zero (related to the pick-up time of the relay) to send a "pick-up" signal, it is just near the voltage "zero-crossing" point of "pick-up". If a "release" signal is sent a certain time before the current crosses zero (related to the release time of the relay), it is "released" just near the "zero-crossing" point of the current. It's just that the action time of the relay (engagement time, release time) is not very stable, and there will be a little "randomness", so the actual action time is only around the "zero point", not the real "zero point".

However, because the deviation is not large, the spark of electric shock is still greatly improved. So there is a certain use value. View the original post" begging.

1. The relay is an electrical control device, which is an electrical appliance that makes the controlled quantity change in the electrical output circuit when the change of the input quantity (excitation quantity) reaches the specified requirements. It has an interactive relationship between the control system (also known as the input loop) and the controlled system (also known as the output loop). Usually used in the control circuit of automation, it is actually a kind of "automatic switch" that uses a small current to control the operation of a large current.

Therefore, it plays the role of automatic adjustment, safety protection, and conversion circuit in the circuit.

2. Zero-crossing triggering is to change the frequency of thyristor conduction within a set time interval to achieve voltage or power control. The main disadvantage of zero-crossing triggering is that low-frequency interference will occur when the on-off ratio is too small, and when the power grid capacity is not large enough, there will be lighting flickering, meter pointer jitter and other phenomena, which are usually only suitable for electric and thermal loads with large thermal inertia.

Dear, hello, the relays are all control live wires, through the normally open and normally closed contacts of the relay reactors, the control loop live wire is switched on and off to achieve the purpose that the circuit should perform, and all the normally closed or normally open contacts of the relay are control live wires, so thermal relays are no exception to the live wire. First of all, for all AC electrical appliances, whether it is a built-in transformer, switching power supply, or 220V direct access to the load, the free exchange of zero live wires can work normally. The significance of strictly distinguishing between zero lines of fire lies in safety.

For simple loads such as light bulbs, the zero live wire is completely fine; For electrical appliances, if the switch is connected, the zero live wire should be strictly distinguished, so that the switch controls the live wire instead of controlling the zero line; In this way, as long as the switch is turned off, theoretically the electrical appliance will be completely powered off, otherwise the electrical Qingyu will be charged for a long time (although it does not work); In the case described, if there is neither a switch, nor does the appliance have a metal casing, or the enclosure cannot carry Changcha Na, then the appliance may use a two-pin socket without distinguishing between neutral live wires. However, in the process of wiring, the electrician does not know what electrical appliances you will use, so in the wiring process, it is strictly required to distinguish between zero live wires, and the socket must be left zero and right fire; For electrical appliances such as fixed-frequency air conditioners, although the zero live line can work in reverse, the relay inside the appliance may only control one pole of the compressor. If the zero live wire is reversed, the compressor will be charged for a long time (although it does not work), at this time, if the terminal leaks and the relay is connected to the ground, then the compressor may work out of thin air, which is very dangerous;

The G5NB-1A DC12V is a 1-pole, 3A open and closed compact power relay with an impulse voltage of 10 kV.

The G5NB and G4A are internal models** of Omron relays, and the G5NB is a relay for printed substrates with a contact configuration of 1A and a maximum contact current of 3A.

1a indicates that the number of contact poles is 1 pole, and the contact composition is DC 12VG4A-1A-PE, which is a 1-pole small power relay that realizes 80 A of power-on, power-on, and 20 A of cut-off.

This is a relay for printed circuit boards with a contact configuration of 1A and a maximum contact current of 20A.

Choosing a relay is very simple, you mainly look at how much the coil voltage is 12V or 24V or 220V, whether it is AC or DC, and then see how many feet it is, and you can replace it by buying a similar one. G5NB-1A4DC12V can be seen to be DC12V, count how many pins there are, just buy a DC12V, the relay with the same number of pins can be. G4A-1A-PE, the same coil voltage coil is written, the number of pins is counted by yourself, it's as simple as that.

The voltage is larger than BAI and is DC, and it is recommended to DUs

It's not to use zhi like that.

Because the relay is disconnected or touched at the point of contact.

If it is alternating current, then because it has the characteristics of periodic voltage zeroing, there is no problem with the withstand voltage, and it can be elevated. However, due to the constant voltage of direct current, the arc may always exist, and the arc can only be extinguished when the contact gap is restored to a large position so that the arc cannot break through the gap. Therefore, the nominal withstand voltage of direct current is generally relatively low.

Back to your question, the withstand voltage of the relay is 30VDC, no matter whether you use the current to reach 10A or not, as long as your DC voltage exceeds 30VDC, then there is a contact arc of the relay that cannot be extinguished, and there is a great safety hazard. It is recommended that you replace the relay with one model.

Then you can use the 5a one!! A 10A relay is much more expensive than a 5A relay!

Is 48V DC or AC, and is the load inductive?

Relays that meet this function are called magnetic latching relays.

The normally closed or normally open state of the magnetic latching relay completely depends on the action of permanent magnets, and the conversion of its switching state is triggered by a pulse electrical signal of a certain width. The magnetic latching relay will be permanently engaged as long as it is a forward voltage (pulse), and does not require a voltage of protection. In order to release, a reverse (impulse) voltage must be added.

There is also a kind of double-line circle product, one line is dedicated to forward voltage suction, and the other line is specially added to reverse voltage release.

The principle of magnetic latching relay: the magnetic latching relay is engaged after the excitation coil is energized (DC), and the excitation coil is powered off, and it still remains in the suction state under the action of remanence. If a suitable reverse current is added to the excitation coil to eliminate the effect of remanence, the relay can be released.

In practical applications, it is very inconvenient to have only a coil, so the magnetic latching relay usually has two coils, one is used for sucking up and the other is used for release, and the specific working voltage refers to the magnetic latching relay product manual.

Products: Such as Omron G2R series 1-pole 10A 2-pole 5A magnetic latching power relay.

If you give it an instantaneous current, it will only be instantaneously attached, unless there is a self-locking, you say that you will give it an instantaneous current, either in adding a relay, or controlling the original one to give it a loss of voltage signal, this simple is probably a CPU emits high and low levels to control the conduction or cut-off of a tube, remember to give points.

Direct current ionization effect, relay contacts are easy to oxidize.

Solid state relay foreign brands: Crydom in the United States, Kara in Switzerland, Omron in Japan.

First of all, let's talk about our neighbor - Japan, it's not that I have a prejudice against Japan, Japan's things are really rubbish, and the materials can be as much as they can be saved, and the solid state hates to have to use heat sinks, so use a very small aluminum plate to dissipate heat, of course, the product performance is not good, but the island country is poor in resources, forget it, don't mention it.

The originator of Crydom solid-state in the United States is really a solid-state expert, and the process shape and performance have not been said, and they have never seen it bad.

The quality of Jiale is the same as that of Crydom, and the appearance is particularly unique.

The voltage is normal to make a 1500V, the current is 800A, and the switching speed is less than 10ms

Solid state relays have seen double-breaks, small ampere, Jiangsu Norton, high-current I haven't seen, but I've seen three-breaks, isn't it three-phase.