Product Categories

Contact Us

Add: No.38 South Taoyuan Road, Yaozhuang Town,Jiashan County, Jiaxing City, Zhejiang Province, China
Contact person: Elva Zhuang&Sunny Ni
Tel:+86-573-84775555
Fax:+86-573-84776699
Phone:+86-13732570078
E-mail:sales9@great-relay.com
       sunny.ni@great-relay.com

Latching Relay

Home > News > Content
Use Relay And Solenoid To Save Power
Nov 24, 2017

Use relay and solenoid to save power

When designing drive circuits for inductive loads, factors such as size, cost, switching speed, reliability, power consumption and heat dissipation should be taken into account. This paper discusses how to save power by using relays and electromagnetic coils. The inductive load, such as relay or electromagnetic coil, needs a certain amount of electric energy to excite the load. Once the excitation is completed, the required electric energy can be reduced, while the load remains active.

Many factors need to be considered when choosing a specific design method, and these factors are not always independent of each other. When designing drive circuits for inductive loads, size, cost, switching speed, reliability, power dissipation and heat dissipation should be considered.  Inductive loads such as relays or electromagnetic coils are different from simple resistive or capacitive loads. They require a certain amount of electrical energy to excite the load. Once the excitation is completed, the required electric energy can be reduced, while the load remains active. The extra advantage of low current is that the load can be stopped in a short time.


In my previously published blog article "back EMF and buffer", I discussed one aspect of the switch type inductive load, and suggested that you follow my train of thought and continue to discuss the buffer. Whether you choose to disconnect the power of the inductive load, the back EMF (back-EMF) always exists.


In applying the following techniques, not all perceptual load data manuals can provide sufficient information. In fact, when I collected data for this blog, there was almost no data book that had such information. However, the SchrackRT2 series relay provides a good example. As you can see, there is a big difference between the pull in voltage, the relay, and the requirement to keep the load in the active state.

The lack of information means that almost all of the design you do can only be "try again."". Once you really determine the method and the amount you want to use, you have to consider the amount of change due to the production expansion, voltage changes and temperature / humidity changes. If possible, I recommend choosing the product that provides the parameters.


Control the inductive load and adjust the voltage on the coil or change the current. If you want to do it all yourself, you can use the following methods. Fig. 2 is only a conceptual display. For bipolar transistors (BJT), there must be a current limiting resistor on the transistor


Add: No.38 South Taoyuan Road, Yaozhuang Town,Jiashan County, Jiaxing City, Zhejiang Province, China
Contact person: Elva Zhuang&Sunny Ni
Tel:+86-573-84775555
Fax:+86-573-84776699
Phone:+86-13732570078
E-mail:sales9@great-relay.com
       sunny.ni@great-relay.com