5 電磁鐵的用途，使用電磁鐵的環境特殊要求，如溫度; 濕度; 沖擊; 振動; 加速度等
2． 照激磁線圈供電的種類： 直流、交流
5. 按磁路的形狀： 開路導磁體如螺管式；閉路導磁體如盤式（起重電磁鐵）、拍合式、Ⅱ型、Ⅲ型（及E型）、裝甲螺管式
E 型： 行程介于上兩者之間
DC solenoids, hydraulic solenoid valve, solenoid water valve, solenoid pump
The followings are the relationship between force and resistance, current, and voltage. The power is related to the size of wire and the number of windings wire produces stroke.
The shorter the stroke is the bigger the force is. When inquiring force, you must mention the stroke, because they are directly relevant.
Normally, the stronger the power the greater the force is. Both of them have direct ratio. But, when power reaches a certain level that solenoid approaches magnetic saturation, the force increase little.
If the resistance, current and voltage vary while the power and coil remain the same. The force remains.
a. If the coil resistance is kept unchanged when increasing the number of windings with bigger size wire, the force will increase. If the original coil is already fully wound, the enameled wire can't be changed, otherwise, the coil will be too bigger to fit into the iron shell.
b. Increasing the number of windings with the same size enameled wire only results in decreased force, because the negative effect on the force of the resistance increase outweighs the positive effect of the increase of the winding number.
c. Changing the enameled wire size (the resistance being changed) but keeping the power (P= U2/R£»R¡¢U being unchanged, but keeping P), we will get unchanged force.
Operation time determines power, that is, if the operation time continues a long period of time, the power can't be set too big, otherwise, solenoid will be damaged by overheating.
If you slect SDO-0837L model solenoid, requiring a stroke of 5mm, 500-g force, not mentioning size and power, we may offer SOD-0837L already in storage in stead of winding for a new solenoid, so as for a quick sample delivery, for instance, selecting the solenoid of 36 ohm.
After the customer has received the product, they power it with regulated power supply, and adjust the voltage (stroke set at 5mm). The force will increase with the voltage increase, and the solenoid will heat up increasingly apparently. When the force reaches 500g, the voltage is 24V. This means that SDO-0837L is able to produce a force of 500g when power is set 16W(242/36=16), stroke 5mm.
If you use 12V power supply, the resistance will be changed to 9 ohm in order to reach the same force while keeping the 16W power (R=U2/W=122/16=9). For 16W power, the solenoid produces more heat than permited. Or the limited temperature rises value(usually ambient temperature +65° or the current exceeds that customer permits, a bigger sized solenoid shall be selected to avoid that overheating.
The adoption of above methods will reduce the number of sample delivery due to resistance changes.
For high sample success rate, customers are kindly required the following conditions for solenoid use.
Maximum stroke, force requirement, voltage (or current and resistance), expected life (total operation times within operational life), application purpose (for what equipment), and other information that can be offered