2SA Datasheet PDF Download – Silicon PNP Transistor Epitaxial Planar Type(PCT PROCESS), 2SA data sheet. 2SA datasheet, 2SA circuit, 2SA data sheet: KEC – Silicon PNP Transistor Epitaxial Planar Type(PCT PROCESS),alldatasheet, datasheet. datasheet search, datasheets, Datasheet search site for Electronic Components and Semiconductors, integrated circuits, diodes and other semiconductors.

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Also from what I’ve read, Ge transistors are prone to eairly demise.

Q1 and Q2 are arranged with positive feedback so that they have two stable operating points. Now you have to go back and update the min required current sink value for Q1, and ripple thru all the downstream calculations from that as shown above. That shorts the base of Q1 to ground, turning it off. Glade s2a1273 worked for ya.

Email Required, but never shown. Figure another mV for Q4 when saturated, leaving 2. Since you haven’t specified speed, there is no way to say whether 5. Post Your Answer Discard By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies.

With R4 of 5. The main job of Q1 is to turn on Q4, so it can power the load. Q2, Q4 is 2SA Looking for Germanium Transistor for Rovio. That sounds high for a minimum guaranteed gain, but I’ll take your numbers at face value.


This can work for different values of the resistors 2da1273, R3, R7, R8. I’d round down to the next common value of 2. Thanks for the feed back. When Q1 is off, Q2 is off, which then does not try to turn on Q1.

Changing R2, R3 will make the latch work or not. That’s the main current that Q1 needs to be able to sink when on. Since R3 only needs to react “instantly” on a human time scale, there is no need to make R3 small.

Content is read only for historical purposes. Sunday, 30 May You haven’t provided a datasheet for the 2SA, so we’ll arbitrarily assume they can be counted on to have a gain of at least Picked up a dozen just in case from a guy on ebay.

To do even better I’d use some CMOS logic based circuit because that will be miles better regarding power consumption.

latch – What is the difference between the circuits? – Electrical Engineering Stack Exchange

Each transistor being on keeps the 2aa1273 on. Anyone know where I can pick up one of these bad boys? When SW2 is pressed, it turns on Q3. That results in I am assuming that there should be another one on the circuit board. You can get them from Newark at this link: I think that for both sets of resistor values the datashewt will work.

Please post the readings and I’ll try to help you find a replacement. I’m not a fan of the 5.


2SA1273 Datasheet, Equivalent, Cross Reference Search

The circuit basically consists of 3 sections: When SW1 is pressed for a little while, Q1 is turned on. Hope this helps you out. That large current isn’t really needed.

Once you understand what each part does, you’ll be able to find acceptable values for them yourself. But then you’re near the edge of what this PNP can do. Post as a guest Name. I can’t find a relacement or equivilent. The lowest voltage drop for such a LED would be 1. Try to find one and pull it out of the circuit and check the pin lay out and measure it’s B to C and B to E. From inspection, we can see that the current to drive Q2 can be much smaller than that.

What is the difference between the circuits? Soldered it in and voila, works perfectly. Note how the suggested by OP resistor values aren’t that well chosen. I 2wa1273 the trigger latch circuit: I would therefore use 3. That means a total of at least 1. Added You now say that you want to support a final load current 2sa12773 mA, and that the gain of Q4 is OK I found it.

I’ve read that for the most part silicon tranistors are drop in replacements. Sign up using Email and Password. Olin Lathrop k 30

Last modified: May 27, 2020