UJT Characteristics Apparatus
Product Code : SCL-EAE-11325
Quick answer: The UJT Characteristics Apparatus is used to plot the emitter characteristic of a unijunction transistor, emitter voltage against emitter current at a set inter-base voltage, and to locate the peak point, negative-resistance region and valley point. It also introduces UJT triggering and relaxation oscillators. Lab Exports manufactures it in Delhi for schools, colleges and universities.
Specifications
| Parameter | Detail |
|---|---|
| Device studied | Unijunction transistor (UJT) |
| Device terminals | Emitter, base one (B1) and base two (B2) |
| Apparatus type | Semiconductor characteristics laboratory apparatus |
| Primary measurements | Emitter voltage and emitter current |
| Primary experiment | Plotting the UJT emitter characteristic |
| Brand | Lab Exports |
How the UJT characteristics experiment is done
A unijunction transistor has a single PN junction between the emitter and a lightly doped bar that carries the two base connections, B1 and B2. With a voltage VBB applied between the bases, the emitter stays reverse biased and draws very little current until the emitter voltage reaches the peak-point voltage, Vp = eta x VBB + VD, where eta is the intrinsic stand-off ratio and VD the junction drop.
Beyond the peak point the emitter current rises while the emitter voltage falls, a negative-resistance region that ends at the valley point. After the valley point the device behaves like a forward-biased diode. This switching action makes the UJT a simple trigger device for relaxation oscillators and SCR firing circuits.
- Identify the emitter, B1 and B2 terminals on the apparatus and set the supplies to zero.
- Apply a chosen inter-base voltage VBB and keep it constant.
- Increase the emitter supply slowly, recording emitter voltage and emitter current at each step.
- Note the peak voltage where the emitter voltage stops rising, and the valley point where it starts to rise again.
- Repeat at another VBB and plot both emitter characteristics on one graph.
Comparing the curves for two inter-base voltages shows the peak-point voltage rising with VBB, which lets students estimate the intrinsic stand-off ratio.
Key features
- Practical observation of emitter voltage against emitter current over the full UJT curve
- Locates the peak point where significant emitter conduction begins
- Makes the negative-resistance region visible between the peak and valley points
- Valley-point identification marks the change to the conducting region
- Reinforces terminal identification of emitter, base one and base two
Documentation and supply
Most Lab Exports products carry a one-year manufacturer warranty.
Lab Exports manufactures the UJT Characteristics Apparatus at its works in Laxmi Nagar, Delhi, and supplies it to schools, colleges and universities in India and 60+ countries, handling the export documents for each shipment. More about the company is on the About Lab Exports page.
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The full range is in the Electrical and Electronics section of the Physics Lab range.
Frequently asked questions
What is the negative-resistance region of a UJT?
It is the part of the emitter characteristic between the peak and valley points, where emitter current increases while emitter voltage decreases.
What does the UJT characteristics apparatus measure?
Emitter voltage and emitter current at a set inter-base voltage, from which the peak and valley points and the intrinsic stand-off ratio can be estimated.
What is the price of the UJT Characteristics Apparatus?
Prices are not published on the website. Add the UJT Characteristics Apparatus to the Enquiry Cart with the Add To Cart button on this page, or email [email protected] with the house code SCL-EAE-11325 and the quantity, to receive a quotation.
Does Lab Exports manufacture the UJT Characteristics Apparatus?
Yes. Lab Exports manufactures the UJT Characteristics Apparatus at its works at 11/315, Lalita Park, Laxmi Nagar, Delhi 110092, under house code SCL-EAE-11325.
Request a quote
Email [email protected] with the house code SCL-EAE-11325 and the quantity, or add the UJT Characteristics Apparatus to the Enquiry Cart with the Add To Cart button on this page. Tender buyers can also see the Tenders and OEM page.
