2.1 Classification on the standard of the operation principle or the structure features. Showing in tablet 1. (only list the classifications that Hongfa produces or will develop soon)
(Table 1)

No.

Name

Definition

Electromagnetic relays

Relays that operate “on”、“off” or changeover by the magnetism produced by the control current putted to the coil.

1

Electro-

magnetic relay

DC

The control current is direct current. According to the contact load, it can be classified into four kinds of micro power, low power, intermediate power and high power.

2

AC

The control current is alternating current. It can be classified into two kinds of 50Hz and 400Hz according to the frequency of the coil power source.

3

Magnetic latching relay

Using permanent magnet or parts with high remanence to keep the armature at the same position as the coil is electrified when the coil power source is taken away.

4

Solid state relay (SSR)

SSR is a kind of merely solid-state component that can make the whole circuit “on” or “off” as electromagnetic relays do, and the I/O isolation resistance is equivalent to electromagnetic relays.

5

Hybrid relay

The relay is composed of electronic components and electromagnetic relays. Generally, the input part is composed of electronic circuit playing the role of enlargement and rectification; the output part is electromagnetic relay.

6

High frequency relay

The relay is used in AC circuit whose switching frequency exceeds 10kHz.

7

Coaxial relay

The relay is used together with coaxial cable to switch high frequency and RF circuits. But the power consumption is minimum.

8

Vacuum relay

The contact of the relay is sealed in vacuum container. It is used to fleetly switch on, off, or over high voltage, high frequency and RF circuits.

Thermal relay

The relay acts on the effect of heat.

9

Thermal relay

Temperature relay

The relay will act when the ambient temperature rise to a certain value.

10

Electrothermal relay

The relay will act when the heat energy that is from electricity energy in the controlling circuit rise to a certain value.

11

Photoelectrical relay

The relay acts on photoelectric effect.

12

Polarized relay

The relay acts on the effect of the polarized magnetic field and the controlling current through the coil. The operating direct depends on the direct of the coil current.

13

Time relay

When input signal is putted on or taken away, output parts won’t turn the controlled circuit on or off until the time is delayed or limited to a specified spot.

14

Reed relay

The relay opens, closes, or changeovers the circuit depending on the action of the reed sealed in the tube. The reed acts as both contact blade and armature.

(Table 2)

Definition

Micro power relay

When the off state voltage of contact is 27VDC, the contact rated load current (resistive load) is 0.1A, 0.2A.

Low power relay

When the off state voltage of contact is 27VDC, the contact rated load current (resistive load) is 0.5A, 1A.

Intermediate

power relay

When the off state voltage of contact is 27VDC, the contact rated load current (resistive load) is 2A, 5A.

High power relay

When the off state voltage of contact is 27VDC, the contact rated load current (resistive load) is 10A, 15A, 20A, 25A, 40A, etc.

2.3 Classification on the outline dimension. Showing in table 3.

(Table 3)

Definition

Microminiature relay

The dimension of the longest side doesn’t exceed 10mm.

Subminiature relay

The dimension of the longest side exceeds 10mm, but less than 25mm.

Miniature relay

The dimension of the longest side exceeds 25mm, but less than 50mm.

2.4 Classification on the protective construction. Showing in table 4.
(Table 4)

Hermetic relay

Sealed relay

The contact, coil and other parts are all sealed (not hermetically) in a cover to protect the relay.

Open relay

There is no protective cover to protect the contact, coil and other parts.