Hay Bridge Manufacturer,Supplier and Exporter in India
Product Code : EL-SI-8078
Jlab Export is a leading Hay Bridge Manufacturer,and suppliers in India
Hay Bridge (code EL-SI-8078) is an AC bridge for measuring unknown inductance, especially of high-Q coils, in BSc physics and electrical measurement labs. In a teak wood case it combines a built-in 1 kHz sine-wave source, a null detector with digital display, decade dials for R2, R3 and C, a fixed 100 ohm resistance R4 and 4 unknown values supplied for practice. It is made by Jain Laboratory Instruments Pvt Ltd (JLab) at its works in Ambala, India.
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Specifications
| Parameter | Detail |
|---|---|
| Measures | Unknown inductance (Hay bridge) |
| Case | Teak wood, with all parts built in |
| AC source | Built-in sine-wave signal of 1 kHz; two sockets for the AC output |
| Source controls | Amplitude, switch and indicating lamp on the Bakelite board (listed as “The Amplitude of AC switch indicating lamp is provided on the bakelite board”) |
| Detector | Built-in null detector with digital display, for small AC signals at the output |
| Connections | 4 mm sockets; circuit layout spread out on the board for convenient working and clear understanding |
| R2 and R3 | Three decade dials each: x10, x100 and x1000 ohm |
| C | Decade dial, x0.1 µF (mfd) |
| R4 | Fixed resistance, 100 ohm |
| Unknowns supplied | 4 unknown values |
| Quality check | Each bridge is visually inspected before dispatch |
| Pack quantity | Each (sold individually) |
| Minimum order quantity | 10 units |
| Dispatch time | Usually 7–10 working days |
| Product code | EL-SI-8078 |
| Manufacturer | Jain Laboratory Instruments Pvt Ltd (JLab) — OEM |
| Country of origin | India (made in Ambala, Haryana) |
How Does It Compare with the JLab Maxwell Inductance Capacitance Bridge?
| Model | Capacitor arm | Other arms | Unknowns |
|---|---|---|---|
| This Hay bridge (EL-SI-8078) | C decade dial (x0.1 µF) with R4 fixed at 100 ohm | R2 and R3 variable, x10 to x1000 ohm | 4 supplied |
| Maxwell Inductance Capacitance Bridge | C4 decade dial (x0.01 µF) with R4 decade dial (x10 to x1000 ohm) | R2 and R3 fixed at 1 kilo-ohm; R1 decade dial | Four supplied |
Both are listed with a 1 kHz sine-wave source and a digital null detector. Choose the Hay bridge for coils with a high quality factor (Q), where its series capacitor–resistor arm needs only a small resistance; the Maxwell inductance–capacitance bridge is the usual choice for coils of moderate Q.
What Is the Hay Bridge Used For?
Hay’s bridge is a modification of Maxwell’s inductance–capacitance bridge in which the standard capacitor is in series with a resistance instead of in parallel with it. For a high-Q coil the parallel version would need an impractically large resistance, whereas the Hay arrangement balances with a small one — here the fixed 100 ohm R4. At balance the inductance is very nearly R2 × R3 × C for high-Q coils; the exact equation also contains the source frequency, which the built-in source sets at 1 kHz. The bridge is a standard AC practical in BSc physics and in electrical measurement courses at engineering colleges and polytechnics.
To use it, connect one of the 4 supplied unknowns at the 4 mm sockets, switch on the 1 kHz source and set its amplitude, then adjust R2, R3 and the C dial until the digital null detector reads a minimum. Calculate the inductance and the Q of the coil from the dial values, then repeat with the other unknowns or with your own coils.
What to Specify When Ordering
- Quantity — the minimum order is 10 bridges, supplied individually.
- Mains supply — state your local mains voltage so JLab can confirm the built-in source suits it.
- Other inductance bridges — add Maxwell, Anderson or Owen bridges to the enquiry if your syllabus compares methods.
Frequently Asked Questions
What does the Hay Bridge measure?
Unknown inductance, and it is the preferred bridge for coils with a high quality factor. It uses its built-in 1 kHz source and digital null detector.
What adjustable elements does it have?
R2 and R3 each have three decade dials (x10, x100 and x1000 ohm) and C is a decade dial in steps of 0.1 µF. R4 is a fixed 100 ohm resistance.
Are unknown inductances supplied?
Yes. 4 unknown values are supplied with the instrument for practice measurements.
How does it differ from the Maxwell Inductance Capacitance Bridge?
In the Hay bridge the capacitor is in series with a resistance, which suits high-Q coils; in the Maxwell bridge it is in parallel, which suits coils of moderate Q. The listed dials also differ, as the comparison table shows.
What are the minimum order and dispatch time?
The minimum order is 10 units. Dispatch is usually within 7–10 working days, after each bridge is visually inspected; export transit depends on destination and shipping method.
What does an export quotation need?
The quantity, destination country and port or city, delivery terms such as FOB or CIF, packing or labelling instructions and any tender reference.
Who manufactures it?
Jain Laboratory Instruments Pvt Ltd (JLab) makes the Hay bridge at its works in Ambala, Haryana, India.
OEM Manufacturer
JLab is the trading name of Jain Laboratory Instruments Pvt Ltd, a scientific instruments manufacturer in India, incorporated in 2017 and located on Hargolal Road, Ambala, Haryana. The bridge is built at JLab’s own works rather than bought from a trader, so engineering colleges, universities, dealers and importers buy direct from the maker; each instrument is visually inspected before dispatch, and repeat orders are handled by the manufacturer. JLab exports worldwide and ships to buyers in every region — Peru in South America, Niger in West Africa, Kyrgyzstan in Central Asia, Congo in Central Africa and the Maldives in South Asia among them. Tender buyers can refer to the JLab lab tenders page.
Related Bridges and Accessories
- Owen Bridge — an inductance bridge with two capacitor dials whose balance does not depend on frequency.
- Self Inductance Anderson Bridge — a development of the Maxwell bridge with four unknowns supplied.
- Maxwell Inductance Bridge — compares the unknown with a standard inductance dial instead of a capacitor.
- Three Dial Inductance Box — a dial-type inductance box for further known inductances.
- Head Phone — flexible headphones with high-resistance receivers, a traditional audio null detector.
Find more in the Scientific Instrument range and the Indian Instruments section.
Request a Quote
JLab quotes for the Hay bridge directly as its manufacturer. Use the Add To Cart enquiry button on this page, or send the quantity (minimum 10 units), your mains voltage, any other bridges you need and your delivery location through the contact page.
Last updated: 8 October 2026
