# Connect two thyristor in parallel

#### Momentory

Joined Sep 4, 2022
67
I have 2 btw69-1200 thyristor

- Vrrm = 1200v
- Irms = 50A
- I tsm ( Non repetitive surge peak on-state current ) = 610 (8.3 ms) - 580 (10 ms)

Here is the datasheet

https://pdf1.alldatasheet.com/datasheet-pdf/view/93491/STMICROELECTRONICS/BTW69-1200.html

My project needs high current thyristor like 70tps12 but unfortunately not available in my country

- can i connect two btw69-1200 thyristors togather in parallel to get higher current surge?

How to sum the max Itsm ( current surge ) after parallel connection?

- will the Vrrm decrease in parallel connection?

#### Danko

Joined Nov 22, 2017
1,492
- can i connect two btw69-1200 thyristors togather in parallel to get higher current surge?
Use one thyristor. It can work with repetitive surge pulses 270 A max with pulse duration 10 ms.
Your pulse is only 2 ms, so thyristor has big spare by current at 100 A amplitude.
In this circuit thyristor will dissipate 11.5 W, so mount it on appropriate heatsink.

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About connected in parallel thyristors: https://electronicscoach.com/parallel-operation-of-thyristor.html#:~:text=More simply, we can say,connected in a parallel configuration.

Last edited:

#### Momentory

Joined Sep 4, 2022
67
Use one thyristor. It can work with repetitive surge pulses 270 A max with pulse duration 10 ms.
Your pulse is only 2 ms, so thyristor has big spare by current at 100 A amplitude.
Thyristor will dissipate 11.5 W, so mount it on appropriate heatsink.

View attachment 278592___View attachment 278598
About connected in parallel thyristors: https://electronicscoach.com/parallel-operation-of-thyristor.html#:~:text=More simply, we can say,connected in a parallel configuration.

Here is my circuit stimulation

(Sorry i have not circuitlab membership to share the link)

It should send a pulse then 1-2 sec no pulse then a pluse in 10 minutes

So can one thyristor btw69-1200 stand with this?

#### Orson_Cart

Joined Jan 1, 2020
86
Ideally - if you have to parallel - you need an air cored inductor, say 500nH - 1uH in series with each anode - this will help the current sharing at the high peak current turn on event.

#### PAG

Joined Jun 20, 2018
2
I have 2 btw69-1200 thyristor

- Vrrm = 1200v
- Irms = 50A
- I tsm ( Non repetitive surge peak on-state current ) = 610 (8.3 ms) - 580 (10 ms)

Here is the datasheet

https://pdf1.alldatasheet.com/datasheet-pdf/view/93491/STMICROELECTRONICS/BTW69-1200.html

My project needs high current thyristor like 70tps12 but unfortunately not available in my country

- can i connect two btw69-1200 thyristors togather in parallel to get higher current surge?

How to sum the max Itsm ( current surge ) after parallel connection?

- will the Vrrm decrease in parallel connection?

#### PAG

Joined Jun 20, 2018
2
What you need is a current splitter: a center-tapped inductor in which the two ends of the inductor are connected to the thyristors, and the center tap is connected to the load. The inductor will present an impedance in series with the first thyristor to turn on. When the second thyristor turns on, the center-tapped inductor will act like a transformer (with the two windings opposing one another) as the thyristor picks up the load. The inductor must be sized to support full load current, but only needs to act like an inductance for the time differential between the first thyristor turn-on and the second thyristor turn-on. Let's say that time difference is 5 µS at worst. Then in order to support 1200 volts for 5 µS, the inductance must be 120 µH and must not saturate during that time. Henry's Law: L[di/dt] = -V. I used this technique in order to ensure that two power diodes could share a single load because if the diodes were merely paralleled, eventually the first one to turn on would eventually short-circuit.