Electronic Components Datasheet Search |
|
AN308 Datasheet(PDF) 5 Page - STMicroelectronics |
|
AN308 Datasheet(HTML) 5 Page - STMicroelectronics |
5 / 16 page AN308 Triggering methods 5/16 The second triggering pulse occurs at point C when θ + α = 240°. It has no action on the TRIAC which is still conducting. The TRIAC is not turned on for the next half-wave. As in the previous case, the operation is totally asymmetrical, and thus unacceptable. Figure 6. Synchronization by the mains voltage - asymmetrical operation θ < ϕ To prevent this fault, it is necessary to limit the turn-on angle to maintain θ > ϕ. This is possible for loads whose L and R parameters remain strictly constant. Experience shows that for the majority of inductive loads used in industrial applications (like motor controls and transformers) the values of L and R are not constant and vary a great deal during operation. For these types of applications it is not possible to limit the turn-on angle without considerably reducing the voltage excursion. To sum up, this simple triggering circuit, synchronized by the mains voltage, is more developed than the previous one. It has the following charactersitics: ● Advantages: – Simple design – More accurate control than the previous circuit – No auxiliary power supply or transformer required ● Disadvantages: – Connection of the circuit by 3 marked wires, instead of 2 without polarity in the previous circuits – Higher power dissipated in passive components P and Rt (since the mains voltage is continuously applied across them) – Operation becomes completely asymmetrical if the control angle θ is less than ϕ. This triggering circuit can be used only for applications in which the phase shift of the load remains constant (air inductor) or if operation is restricted to values of θ much higher than ϕ, that is, for low load voltage operations. full angle Mains voltage Gate pulse B ϕ T T T α θ C θ TRIAC voltage TRIAC current |
Similar Part No. - AN308 |
|
Similar Description - AN308 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |